docs: add skills directory and update README index

Add three packaged .skill files and document them in README:
dolgolyov-claude-facts, dolgolyov-git-release-publisher, feature-planner.

README.md

@@ -1,6 +1,6 @@
 # Claude Code Facts
 
-> Last updated: 2026-03-24
+> Last updated: 2026-03-25
 
 A collection of interesting and useful facts, tips, tools, and guides for working with Claude and Claude Code.
 
@@ -17,3 +17,11 @@ Reusable reference for building CI pipelines, release automation, and installer
 ### [Windows Code Signing for Open-Source Projects](windows-code-signing.md)
 
 Review of code signing options for Windows executables — Azure Trusted Signing ($9.99/mo, immediate SmartScreen trust), SignPath.io (free but GitHub-only), SSL.com, Certum, and self-signed. Includes CI/CD integration examples for Gitea Actions.
+
+## Skills
+
+Packaged Claude Code skills (`.skill` files) in the [skills/](skills/) directory:
+
+- **dolgolyov-claude-facts** — Sync local project configuration with the central claude-code-facts knowledge base.
+- **dolgolyov-git-release-publisher** — Generate release notes and push release tags for repos hosted on Gitea or GitHub.
+- **feature-planner** — Plan and develop complex features using a structured, phase-based workflow with git integration, Markdown plans, review gates, and controlled merging.