[FEATURE] Add agent skills

Describe what the feature does

Most developers today use agents to generate code.

I propose adding an official Motion / Animation skill that enables agents to reliably generate, structure, and reuse animation-related code.

Provide a code example of what the feature should look like

Remotion provides a strong reference implementation for how official skills can be structured and maintained.

https://github.com/remotion-dev/skills/tree/main/skills/remotion

Describe alternatives you've considered

None

Additional context

Initial scope could focus on common anime.js patterns.