chore: move skill into SKILL.md

[markmcd]

By following the skill spec, and putting the skill definition in a SKILL.md file, the Colab skill will be installable via community tools, e.g. npx skills install ... and indices like https://skills.sh/. This also allows the skill to be version managed (i.e. skills-lock.json) and updated (npx skills update).

I've also added an installation instruction to the skill so that users who stumble upon the tool via the skill have a path to onboard.

Tested, compare:

$ npx skills install markmcd/google-colab-cli#skill-md
...
◇  Installation complete
│
└  Done!  Review skills before use; they run with full agent permissions.

$ tree .agents/skills/colab-operator/
.agents/skills/colab-operator/
└── SKILL.md

$ gemini -p "write a python fibonacci function and run it in a remote colab kernel, then give me the 103rd number" --yolo
... etc :)

with:

$ npx skills install googlecolab/google-colab-cli
...
┌   skills
│
◇  Source: https://github.com/googlecolab/google-colab-cli.git
│
◇  Repository cloned
│
◇  No skills found
│
└  No valid skills found. Skills require a SKILL.md with name and description.

lmkwyt!

[sethtroisi]

Thanks for the PR.

In the future, we'd love for contributors to open issues or start a discussion first.

In general we are excited about increasing skill usage. Thanks for testing this out.

Are you familiar with any other projects having their SKILL files nested in a folder? Any example from a mature project would make this an immediate merge from me. I can also look around if you don't have an example.

[markmcd]

Happy to move this to an issue if you like (and sorry, mb!) For prior art, I published this repo: GitHub, skills.sh

Even though it's a bare skill repo, it still needs the skills/ dir to be noticed by popular tooling.