docs: sync skill catalog counts

[dajiaohuang]

Summary

• Update the open-source sponsors page from 150 to the current 163 skills.
• Add the waypoint-bio skill to docs/skills.md so the catalog covers all 163 skill directories.

Type of change

• Documentation

Skills touched

• none

How this was tested

• uv run skills-ref validate passed for all 163 skills with PYTHONUTF8=1.
• uv run --with pytest python -m pytest tests/_meta -q ran 1211 subtests; the only failures are the repository's shell executable/bash checks because this Windows host has no WSL/bash.
• Verified 193 relative links in README.md and docs/*.md; 0 broken.

Notes for reviewers

This is a documentation-only synchronization with the 163 immediate directories under skills/.