feat: add first-party skills, ponytail lock, and full lint suite

- add ponytail skill set to skills-lock.json (14 locked skills total)
- add first-party medusa skill under skills/, layered on install
- make test now runs ruff, shellcheck, and markdownlint-cli2
- CI installs the lint tools before make test in both workflows
- MIT license, funding buttons, thanks and donation sections in README
- .markdownlint-cli2.jsonc config; ignore lint caches in .gitignore

README.md

@@ -1,20 +1,73 @@
 # skills 🧠
 
-Reproducible agent skill collection, pinned in `skills-lock.json`.
-Works for Claude Code, Codex, Gemini CLI, Cursor, Copilot, Windsurf, Cline, and more.
+[![GitHub Sponsors](https://img.shields.io/badge/Sponsor-GitHub%20Sponsors-blue?logo=github)](https://github.com/sponsors/kevinveenbirkenbach) [![Patreon](https://img.shields.io/badge/Support-Patreon-orange?logo=patreon)](https://www.patreon.com/c/kevinveenbirkenbach) [![Buy Me a Coffee](https://img.shields.io/badge/Buy%20me%20a%20Coffee-Funding-yellow?logo=buymeacoffee)](https://buymeacoffee.com/kevinveenbirkenbach) [![PayPal](https://img.shields.io/badge/Donate-PayPal-blue?logo=paypal)](https://s.veen.world/paypaldonate)
 
-Homepage: [github.com/kevinveenbirkenbach/skills](https://github.com/kevinveenbirkenbach/skills)
+The agent skill collection of Kevin Veen-Birkenbach.
+Every skill is pinned in `skills-lock.json` for reproducible installs.
+First-party skills live under `skills/` and are layered on top of the locked ones at install time.
+Compatible with Claude Code, Codex, Gemini CLI, Cursor, Copilot, Windsurf, Cline, and other agents.
 
-## Usage 🚀
+## Requirements 📦
 
-- `make install` installs the skills globally into your home (`~/.agents/skills` and `~/.claude/skills`).
-- `make project TARGET=/path/to/repo` copies the skills into a project (`<repo>/.agents/skills` and `<repo>/.claude/skills`).
-- `make update` refreshes every skill to its latest version and rewrites `skills-lock.json`.
-- `make test` validates `skills-lock.json` and shellchecks the scripts; CI runs it on every push and after every update.
+- Node.js (provides `npx skills`).
+- `jq` (only required for `make update`).
 
-Node.js is REQUIRED (`npx skills`); `make update` additionally needs `jq`.
-Restart your agent after installing so it loads the new skills.
+## Installation 🚀
+
+Install the skills globally into your home (`~/.agents/skills` and `~/.claude/skills`):
+
+```bash
+make install
+```
+
+Copy the skills into a specific project (`<repo>/.agents/skills` and `<repo>/.claude/skills`):
+
+```bash
+make project TARGET=/path/to/repo
+```
+
+Restart your agent afterwards so it loads the new skills.
+
+## Maintenance 🔧
+
+Refresh every skill to its latest version and rewrite `skills-lock.json`:
+
+```bash
+make update
+```
+
+Validate `skills-lock.json` and shellcheck the scripts (also run by CI on every push and after every update):
+
+```bash
+make test
+```
+
+## Related Tools 🧰
+
+This collection is part of a wider toolset for managing IT and infrastructure:
+
+- [alias](https://github.com/kevinveenbirkenbach/alias) — shell aliases for common commands.
+- [package-manager](https://github.com/kevinveenbirkenbach/package-manager) — `pkgmgr`, a single command to install and manage these repositories.
+- [infinito-nexus](https://github.com/kevinveenbirkenbach/infinito-nexus) — automation platform for self-hosted infrastructure.
+
+## License 📜
+
+MIT License, Copyright (c) 2026 Kevin Veen-Birkenbach.
 
 ## Author 👤
 
 Kevin Veen-Birkenbach [kevin@veen.world](mailto:kevin@veen.world)
+
+## Thanks 🙏
+
+Thanks to the [#ai:infinito.nexus](https://matrix.to/#/%23ai:infinito.nexus) community, and especially to [Paulinhx](https://github.com/Paulinhx) for the inspiration.
+
+## Donation ❤️
+
+If these tools help you, consider supporting their development:
+
+- [GitHub Sponsors](https://github.com/sponsors/kevinveenbirkenbach)
+- [Patreon](https://www.patreon.com/c/kevinveenbirkenbach)
+- [Buy Me a Coffee](https://buymeacoffee.com/kevinveenbirkenbach)
+- [PayPal](https://s.veen.world/paypaldonate)
+- Bitcoin: [bc1qle7j8m9kvny2h2q3jzsnc64s4f5zme5re23pzc2lc2d7hhasc4dqachflp](bitcoin:bc1qle7j8m9kvny2h2q3jzsnc64s4f5zme5re23pzc2lc2d7hhasc4dqachflp?message=%E2%9D%A4%EF%B8%8F%20Help%20Build%20the%20Future%20-%20Donation%20to%20Kevin%20Veen-Birkenbach.)