docs: the Action card overstated what CI enforcement does

The "GitHub Action" card said the Action is "enforcement in CI that a
contributor cannot skip". Two other places on the same page are careful
about this -- the pricing note says the only way Commit Check blocks a
merge is if you make it a required check, and the FAQ says to make the
Action or the App a required status check -- so the card was the odd one
out, and the one a reader meets first.

An Action that is not a required status check runs and reports and merges
anyway. The new wording keeps the contrast the card was drawing with the
pre-commit hook above it, which a contributor genuinely can skip with
--no-verify, and states the condition for blocking a merge:

  Runs in CI whether or not the hook ran. Make it a required check and a
  violation cannot merge, with per-rule outputs later steps can gate on.

Found by CodeRabbit on #36, which merged before it could be applied there.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018xYa7m3qup5wyN5MaXFgf6

Author: shenxianpeng

docs/index.md

@@ -248,8 +248,8 @@ One policy engine, five places to enforce it. Every one of them reads the same
 
     ---
 
-    Enforcement in CI that a contributor cannot skip, with per-rule outputs
-    later steps can gate on.
+    Runs in CI whether or not the hook ran. Make it a required check and a
+    violation cannot merge, with per-rule outputs later steps can gate on.
 
     [:octicons-arrow-right-24: Guide](guides/github-actions.md)