Small tweaks to CLAUDE.md

Author: TheBlueMatt

CLAUDE.md

@@ -15,7 +15,11 @@ See [README.md](README.md) for the workspace layout and [ARCH.md](ARCH.md) for s
   of the full task you might prompt the user whether they want you to run the
   full CI tests via `./ci/ci-tests.sh`. Note however that this script will run
   for a very long time, so please don't timeout when you do.
-- Run `cargo +1.75.0 fmt --all` after every code change
+- Run `cargo +1.75.0 fmt --all` before committing code changes. If rust 1.75.0 is
+  not installed, skip this step.
 - Never add new dependencies unless explicitly requested
 - Please always disclose the use of any AI tools in commit messages and PR descriptions using a `Co-Authored-By:` line.
 - When adding new `.rs` files, please ensure to always add the licensing header as found, e.g., in `lightning/src/lib.rs` and other files.
+- When adding comments, do not refer to internal logic in other modules, instead
+  make sure comments make sense in the context they're in without needing other
+  context.