Instruct Claude to use comments more sparingly (#23181)

Author: AlexWaygood

CLAUDE.md

@@ -76,3 +76,4 @@ When working on ty, PR titles should start with `[ty]` and be tagged with the `t
 - Avoid falling back to patterns that require `panic!`, `unreachable!`, or `.unwrap()`. Instead, try to encode those constraints in the type system.
 - Prefer let chains (`if let` combined with `&&`) over nested `if let` statements to reduce indentation and improve readability.
 - If you *have* to suppress a Clippy lint, prefer to use `#[expect()]` over `[allow()]`, where possible.
+- Use comments purposefully. Don't use comments to narrate code, but do use them to explain invariants and why something unusual was done a particular way.