docs: add RAC docs to S2 skill, and clean up (#10083)
* copy RAC docs into S2 skill references directory
* clean up react-spectrum-s2's SKILL.md
* reduce size of Components section by removing descriptions and full links
* make TS output in markdown tables have deterministic orderings (reduce false positives in skills diff comment)
* markdown output cleanup
* remove some redundant skill content
* move Agent Skills above MCP Server in ai docs
