refactor(workflows): rename sync workflow and add README sync

- Rename sync-claude-plugin.yml to sync-skills.yml
- Rename sync-marketplace.js to sync-skills.js
- Update script to also sync README skills table
- Add SKILLS:START/END markers for reliable regex matching
- Truncate skill descriptions to 120 chars in README table

.github/workflows/sync-skills.yml

@@ -1,4 +1,4 @@
-name: Sync Claude Plugin
+name: Sync Skills
 
 on:
   push:
@@ -18,11 +18,13 @@ jobs:
         with:
           persist-credentials: true
 
-      - name: Sync skills to marketplace.json
-        run: node .github/scripts/sync-marketplace.js
+      - name: Sync skills
+        run: node .github/scripts/sync-skills.js
 
       - name: Commit changes
         uses: stefanzweifel/git-auto-commit-action@v7
         with:
-          commit_message: "chore: sync marketplace.json with skills directory"
-          file_pattern: .claude-plugin/marketplace.json
+          commit_user_name: Coreybot
+          commit_user_email: coreybot+github-actions[bot]@users.noreply.github.com
+          commit_message: "chore: sync skills with marketplace.json and README"
+          file_pattern: ".claude-plugin/marketplace.json README.md"