expand agent config

Author: jinnovation

AGENTS.md

@@ -7,3 +7,7 @@
 ## General Practices
 
 - Find package dependencies + their APIs in `.cask/` or `~/.emacs.d/`
+- When adding new user-facing functionality, add a new corresponding record to CHANGELOG.md
+- In general, base your implementations and designs off of the Magit package. Its implementation can
+  be found on GitHub.
+- Use stdlib Emacs packages, functions, and interfaces wherever possible.