Rename section to Skills and simplify label

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: janechu

.github/copilot-instructions.md

@@ -135,9 +135,9 @@ The `docs/` directory is a VitePress site for external developers consuming WebU
 
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-## Additional skills
+## Skills
 
-- **Pull request skills** — `.github/skills/pr/SKILL.md`
+- **Pull request** — `.github/skills/pr/SKILL.md`
 
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