Update docs.

README.md

@@ -30,6 +30,19 @@ Run Editor:
 
 Run Player:
 
-Launch `Player.exe --pp path/to/sample-project/Project`
+Launch `Player.exe`
+
+## Portability of Resource Access
+
+The engine needs to somehow locate project resources on launch.
+
+By default, the engine attempts to find `Data`, `Cache` and `CoreData` folders next to the executable.
+However, this behavior may be inconvenient during development:
+* `Data` and `Cache` folders are located in `Project` folder,
+* `CoreData` is located in `bin` folder of `rbfx` repository,
+* The executable is located somewhere in CMake build folder.
+
+This issue can be mitigated by having `ResourceRoot.ini` file.
+See the comments in `ResourceRoot.ini` file in this repository for details.
 
 ![](/screenshot.png)

ResourceRoot.ini

@@ -0,0 +1,18 @@
+# ResourceRoot.ini should be located either in the same directory as the executable file
+# or in any of the parent directories.
+
+# Format of the file:
+# alias1=relative/path/1
+# alias2=relative/path/2
+# ...
+
+# When the engine is looking for a file, it will check these paths from last to first.
+
+# It is recommended to use standard aliases in default order and only customize the paths:
+# - CoreData: files from `rbfx/bin/CoreData` that should always be updated with the engine.
+# - Data: project-specific files that are created and updated by a person.
+# - Cache: project-specific files that are generated by the editor.
+
+CoreData=../rbfx/bin/CoreData
+Data=Project/Data
+Cache=Project/Cache