[Feat] Add first party agent skill

Target Use Case

A first party agent skill that guides agents to use the patterns from react-map-gl and not force raw maplibre-gl-js from training data into the app.

Proposal

Extracted from https://github.com/visgl/react-map-gl/pull/2593#issuecomment-5110952741, https://github.com/visgl/react-map-gl/pull/2593#issuecomment-5101635060

I suggest to use https://tanstack.com/intent/latest to setup a first party agent skill that handles common pitfalls and gets agents to work within the best practices of react-map-gl.

I have a personal version of this at https://github.com/FixMyBerlin/fixmyskills/blob/main/skills/react-map-gl/SKILL.md which I created and expanded whenever I ran into issues where agents dump raw maplible-gl-js APIs into my react / react-map-gl app instead of using and relying on the react like patterns that react-map-gl provides. I image this can be used as a starting a point.

Start by reading the linked pull request comments and the referenced FixMyBerlin SKILL.md, then compare the proposed TanStack Intent approach with the repository’s existing contributor and usage guidance. Define the first-party skill’s scope and document the react-map-gl patterns it should teach; done means the skill is integrated and covers the stated raw MapLibre API pitfalls.