Add git-commit-guidelines and pr-guidelines skills - #1782

Hi @rayapallisuresh — thanks for adding these two skills! Reviewed at head 54abd11222abe5a8a5a5292f7e9fb21cb7d3c306:

✅ Diff is scoped to .claude-plugin/marketplace.json plus the two new SKILL.md files (29 and 20 lines) — no unrelated changes.
✅ skills/git-commit-guidelines: official validator passes (uvx --from skills-ref agentskills validate skills/git-commit-guidelines → "Valid skill", exit 0); frontmatter name matches its directory; description is 72 chars.
✅ Both marketplace entries parse with jq and match the schema of their neighbors (name, description, source, strict, skills); no duplicate entry names; ./skills/git-commit-guidelines and ./skills/pr-guidelines both exist in the tree at this head, each containing only SKILL.md.
✅ Static scan clean across all added files: no shell=True, os.system, eval, curl | sh, or network constructs; no bundled scripts.
✅ skills/pr-guidelines: the body itself is a solid, concise template (diff-scoped What/Why/Changes).
⚠️ skills/pr-guidelines fails the official validator: "Directory name 'pr-guidelines' must match skill name 'pr-description'". The in-repo quick_validate.py does not check name-vs-directory, so it reports "Skill is valid!" — easy to miss locally, but the published CLI enforces the match.

Suggestions (all non-blocking except #1):

1. Align the name and directory for pr-guidelines — either set the frontmatter name to pr-guidelines, or rename the directory to pr-description and update the marketplace entry accordingly. As shipped, the official validator rejects this skill; this is the one item I would resolve before merge.
2. Add the missing trailing newline at the end of skills/pr-guidelines/SKILL.md (shown as "\ No newline at end of file" in the diff).
3. Marketplace description for pr-guidelines: "and use it" reads as a grammar slip ("and uses it"), and the "use it as a template for future pull requests" promise is not covered in the skill body — either add a step about persisting the description as a template or trim that phrase.
4. Consider adding LICENSE.txt to both new skill directories to match repo convention — 18 of 20 skill directories ship one at this head.

No other blockers; happy to take another look if you push updates.