Doc action event

[oesolberg]

Summary

Added a simple documentation of what functions is involved in making an event action

Description

Added a documentation page and changed the toc for it to appear

Related Issue

Document the template code #2

Motivation and Context

Better documentation for anyone

How Has This Been Tested

No testing

Screenshots (if appropriate)

Types of changes

No code changes

Checklist

• My code follows the code style of this project.
• My change requires a change to the documentation.
• [x ] I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have read the CODE OF CONDUCT document.
• I have added tests to cover my changes if possible
• All new and existing tests passed.

[alexdresko]

Dude, sorry for the delay. I'm catching up, though. Working on pushing a fix for #82 through, then I'll get to this PR. Well done, and super thanks for the contribution!

[alexdresko]

Great additions! I think we'll want to reorganize things a bit once we have more documentation like what you've contributed. It probably deserves its own section, but we'll cross that border when we get to it.