Add a skill

[pirops]

Suggestion: For ease of usage, maybe you should add a skill like this: npx skills add ...

[antono]

I've created 2 codanna skills for myself:

https://github.com/antono/agent-skills/tree/main/codanna-explore
https://github.com/antono/agent-skills/tree/main/codanna-review

Feel free to use. Maybe something like this can be adopted to official codanna skills @bartolli ?