docs(governance): Create changelog files for all of our canisters. (#…

…3388)

Also, moves the description of the process from
governance/unreleased_changelog.md to
nervous_system/changelog_process.md. Other files point to
changelog_process.md.

# Future Work

In the next PRs in this vein, add support for SNS our tools. In
particular, proposal generation, and moving content from
unreleased_changelog.md to CHANGELOG.md.

# References

[👈 Previous PR][prev]

[prev]: #3332

rs/nervous_system/changelog_process.md

@@ -0,0 +1,59 @@
+Each canister has a "primary" code directory (e.g. NNS governance's primary code
+directory is `rs/nns/governance`). Within that directory, there lives two files:
+
+1. `unreleased_changelog.md`
+2. `CHANGELOG.md`
+
+The next section describes how these files are maintained.
+
+# Standard Operating Procedure
+
+1. When a PR introduces user-visible behavior change in release builds (e.g. the
+   PR simply consists of `IS_MY_FEATURE_ENABLED = true`), add an entry to the
+   corresponding `unreleased_changelog.md` file (under the "Next Upgrade
+   Proposal" heading). This new entry should be added in the **same** PR. There
+   is a bot that reminds you to do this.
+
+2. When making an NNS proposal to upgrade this canister (or in the case of SNS,
+   publish a new WASM), copy entries from `unreleased_changelog.md` to the
+   proposal's "Features & Fixes" section. This is handled automatically by our
+   proposal generator scripts.
+
+3. After the proposal is executed, move the entries from
+   `unreleased_changelog.md` to its sibling `CHANGELOG.md` file. This can be
+   done by running
+
+   ```bash
+   PROPOSAL_ID=???
+
+   ./testnet/tools/nns-tools/add-release-to-changelog.sh $PROPOSAL_ID
+   ```
+
+If your new code is not active in release builds (because it is behind a feature
+flag, or it is simply not called yet), then, do NOT add an entry to
+`unreleased_changelog.md`. Instead, wait until your code is actually active in
+release builds (e.g. the feature flag is flipped to "enable") before adding an
+entry to `unreleased_changelog.md`.
+
+
+# How to Write a Good Entry
+
+The intended audience of your new entry is people who vote on NNS proposals. In
+particular, these people are not necessarily engineers who develop this
+canister. In fact, it is best to assume that the reader does not know how to
+program at all. (In fact, very many very intelligent people do not know how to
+write code!)
+
+Look at [this example]. Notice how the only Rust code changes in that PR just
+sets some `IS_MY_FEATURE_ENABLED` "feature flags" to true. The entry being added
+to the `unreleased_changelog.md` file in that same PR describes what the code
+behind the flag does, because suddenly, that code is now active in release
+builds.
+
+[this example]: https://github.com/dfinity/ic/pull/3371/files#diff-a0dc71a90ca0ffb3298781894bae5c9dce11c53078ad815c5df1bec4cf0bf625
+
+
+# The Origin of This Process
+
+This process is modeled after the process used by nns-dapp. nns-dapp in turn
+links to keepachangelog.com as its source of inspiration.

rs/nns/cmc/CHANGELOG.md

@@ -0,0 +1,14 @@
+# Changelog
+
+Proposals before 2025 are NOT listed in here, because this process was
+introduced later. (We could back fill those later though.)
+
+The process that populates this file is described in
+`rs/nervous_system/changelog_process.md`. In general though, the entries you see
+here were moved from the adjacent `unreleased_changelog.md` file.
+
+
+INSERT NEW RELEASES HERE
+
+
+END

rs/nns/cmc/unreleased_changelog.md

@@ -0,0 +1,20 @@
+# How This File Is Used
+
+In general, upcoming/unreleased behavior changes are described here. For details
+on the process that this file is part of, see
+`rs/nervous_system/changelog_process.md`.
+
+
+# Next Upgrade Proposal
+
+## Added
+
+## Changed
+
+## Deprecated
+
+## Removed
+
+## Fixed
+
+## Security

rs/nns/governance/CHANGELOG.md

@@ -3,9 +3,9 @@
 Proposals before 2025 are NOT listed in here, because this process was
 introduced later. (We could back fill those later though.)
 
-The process that populates this file is described in the adjacent
-unreleased_changelog.md file. In general though, the entries you see here were
-moved from there.
+The process that populates this file is described in
+`rs/nervous_system/changelog_process.md`. In general though, the entries you see
+here were moved from the adjacent `unreleased_changelog.md` file.
 
 
 INSERT NEW RELEASES HERE

rs/nns/governance/unreleased_changelog.md

@@ -1,34 +1,8 @@
 # How This File Is Used
 
-1. When there is a user-visible behavior change to this canister, add an entry
-   to this file (in the "Next Upgrade Proposal" section) in the same PR.
-
-2. When making an NNS proposal to upgrade this canister, copy entries to the
-   proposal's summary.
-
-3. After the proposal is executed, move the entries from this file to a new
-   section in the adjacent CHANGELOG.md file.
-
-If your new code is not active in release builds (because it is behind a feature
-flag, or it is simply not called yet), then do NOT add an entry to this file,
-because this new function has no user-visible behavior change yet. Wait until it
-is active (e.g. the feature flag is flipped to "enable") before adding an entry
-to this file.
-
-
-# How to Write a Good Entry
-
-The intended audience here is people who vote (with their neurons) in NNS, not
-necessarily engineers who develop this canister.
-
-If there is a motion proposal and/or forum thread where a feature (or bug fix)
-was proposed, link to it.
-
-
-# The Origin of This Process
-
-This process is modeled after the process used by nns-dapp. nns-dapp in turn
-links to keepachangelog.com as its source of inspiration.
+In general, upcoming/unreleased behavior changes are described here. For details
+on the process that this file is part of, see
+`rs/nervous_system/changelog_process.md`.
 
 
 # Next Upgrade Proposal

rs/nns/gtc/CHANGELOG.md

@@ -0,0 +1,14 @@
+# Changelog
+
+Proposals before 2025 are NOT listed in here, because this process was
+introduced later. (We could back fill those later though.)
+
+The process that populates this file is described in
+`rs/nervous_system/changelog_process.md`. In general though, the entries you see
+here were moved from the adjacent `unreleased_changelog.md` file.
+
+
+INSERT NEW RELEASES HERE
+
+
+END

rs/nns/gtc/unreleased_changelog.md

@@ -0,0 +1,20 @@
+# How This File Is Used
+
+In general, upcoming/unreleased behavior changes are described here. For details
+on the process that this file is part of, see
+`rs/nervous_system/changelog_process.md`.
+
+
+# Next Upgrade Proposal
+
+## Added
+
+## Changed
+
+## Deprecated
+
+## Removed
+
+## Fixed
+
+## Security

rs/nns/handlers/lifeline/CHANGELOG.md

@@ -0,0 +1,14 @@
+# Changelog
+
+Proposals before 2025 are NOT listed in here, because this process was
+introduced later. (We could back fill those later though.)
+
+The process that populates this file is described in
+`rs/nervous_system/changelog_process.md`. In general though, the entries you see
+here were moved from the adjacent `unreleased_changelog.md` file.
+
+
+INSERT NEW RELEASES HERE
+
+
+END

rs/nns/handlers/lifeline/unreleased_changelog.md

@@ -0,0 +1,20 @@
+# How This File Is Used
+
+In general, upcoming/unreleased behavior changes are described here. For details
+on the process that this file is part of, see
+`rs/nervous_system/changelog_process.md`.
+
+
+# Next Upgrade Proposal
+
+## Added
+
+## Changed
+
+## Deprecated
+
+## Removed
+
+## Fixed
+
+## Security

rs/nns/handlers/root/CHANGELOG.md

@@ -0,0 +1,14 @@
+# Changelog
+
+Proposals before 2025 are NOT listed in here, because this process was
+introduced later. (We could back fill those later though.)
+
+The process that populates this file is described in
+`rs/nervous_system/changelog_process.md`. In general though, the entries you see
+here were moved from the adjacent `unreleased_changelog.md` file.
+
+
+INSERT NEW RELEASES HERE
+
+
+END

rs/nns/handlers/root/unreleased_changelog.md

@@ -0,0 +1,20 @@
+# How This File Is Used
+
+In general, upcoming/unreleased behavior changes are described here. For details
+on the process that this file is part of, see
+`rs/nervous_system/changelog_process.md`.
+
+
+# Next Upgrade Proposal
+
+## Added
+
+## Changed
+
+## Deprecated
+
+## Removed
+
+## Fixed
+
+## Security

rs/nns/sns-wasm/CHANGELOG.md

@@ -0,0 +1,14 @@
+# Changelog
+
+Proposals before 2025 are NOT listed in here, because this process was
+introduced later. (We could back fill those later though.)
+
+The process that populates this file is described in
+`rs/nervous_system/changelog_process.md`. In general though, the entries you see
+here were moved from the adjacent `unreleased_changelog.md` file.
+
+
+INSERT NEW RELEASES HERE
+
+
+END

rs/nns/sns-wasm/unreleased_changelog.md

@@ -0,0 +1,20 @@
+# How This File Is Used
+
+In general, upcoming/unreleased behavior changes are described here. For details
+on the process that this file is part of, see
+`rs/nervous_system/changelog_process.md`.
+
+
+# Next Upgrade Proposal
+
+## Added
+
+## Changed
+
+## Deprecated
+
+## Removed
+
+## Fixed
+
+## Security

rs/registry/CHANGELOG.md

@@ -0,0 +1,14 @@
+# Changelog
+
+Proposals before 2025 are NOT listed in here, because this process was
+introduced later. (We could back fill those later though.)
+
+The process that populates this file is described in
+`rs/nervous_system/changelog_process.md`. In general though, the entries you see
+here were moved from the adjacent `unreleased_changelog.md` file.
+
+
+INSERT NEW RELEASES HERE
+
+
+END

rs/registry/unreleased_changelog.md

@@ -0,0 +1,20 @@
+# How This File Is Used
+
+In general, upcoming/unreleased behavior changes are described here. For details
+on the process that this file is part of, see
+`rs/nervous_system/changelog_process.md`.
+
+
+# Next Upgrade Proposal
+
+## Added
+
+## Changed
+
+## Deprecated
+
+## Removed
+
+## Fixed
+
+## Security

rs/sns/governance/CHANGELOG.md

@@ -0,0 +1,14 @@
+# Changelog
+
+Proposals before 2025 are NOT listed in here, because this process was
+introduced later. (We could back fill those later though.)
+
+The process that populates this file is described in
+`rs/nervous_system/changelog_process.md`. In general though, the entries you see
+here were moved from the adjacent `unreleased_changelog.md` file.
+
+
+INSERT NEW RELEASES HERE
+
+
+END

rs/sns/governance/unreleased_changelog.md

@@ -0,0 +1,20 @@
+# How This File Is Used
+
+In general, upcoming/unreleased behavior changes are described here. For details
+on the process that this file is part of, see
+`rs/nervous_system/changelog_process.md`.
+
+
+# Next Upgrade Proposal
+
+## Added
+
+## Changed
+
+## Deprecated
+
+## Removed
+
+## Fixed
+
+## Security

rs/sns/root/CHANGELOG.md

@@ -0,0 +1,14 @@
+# Changelog
+
+Proposals before 2025 are NOT listed in here, because this process was
+introduced later. (We could back fill those later though.)
+
+The process that populates this file is described in
+`rs/nervous_system/changelog_process.md`. In general though, the entries you see
+here were moved from the adjacent `unreleased_changelog.md` file.
+
+
+INSERT NEW RELEASES HERE
+
+
+END

rs/sns/root/unreleased_changelog.md

@@ -0,0 +1,20 @@
+# How This File Is Used
+
+In general, upcoming/unreleased behavior changes are described here. For details
+on the process that this file is part of, see
+`rs/nervous_system/changelog_process.md`.
+
+
+# Next Upgrade Proposal
+
+## Added
+
+## Changed
+
+## Deprecated
+
+## Removed
+
+## Fixed
+
+## Security