Make a Spin agent skill available

[calebschoepp]

I think it would make sense to create an agent skill for Spin. This would make agents work better with Spin and could help with adoption of Spin.

It would be sufficient to have the skill live in the Spin repo and then folks could install it on their system via npx skills add spinframework/spin.

[fibonacci1729]

This sounds reasonable to me. @calebschoepp is this something you would be interested in driving?

[calebschoepp]

If/when I have some time I could get something started. In the meantime if someone else wants to pick this up don't let me stop you.