docs: Update all documentation for multi-platform feature parity
Complete documentation update to reflect multi-platform support across
all 4 platforms (Claude, Gemini, OpenAI, Markdown).
Changes:
- src/skill_seekers/mcp/README.md:
* Fixed tool count (10 → 18 tools)
* Added enhance_skill tool documentation
* Updated package_skill docs with target parameter
* Updated upload_skill docs with target parameter
* Updated tool numbering after adding enhance_skill
- docs/MCP_SETUP.md:
* Updated packaging tools section (3 → 4 tools)
* Added enhance_skill to tool lists
* Added Example 4: Multi-Platform Support
* Shows target parameter usage for all platforms
- docs/ENHANCEMENT.md:
* Added comprehensive Multi-Platform Enhancement section
* Documented Claude (local + API modes)
* Documented Gemini (API mode, model, format)
* Documented OpenAI (API mode, model, format)
* Added platform comparison table
* Updated See Also links
- docs/UPLOAD_GUIDE.md:
* Complete rewrite for multi-platform support
* Detailed guides for all 4 platforms
* Claude AI: API + manual upload methods
* Google Gemini: tar.gz format, Files API
* OpenAI ChatGPT: Vector Store, Assistants API
* Generic Markdown: Universal export, manual distribution
* Added platform comparison tables
* Added troubleshooting for all platforms
All docs now accurately reflect the feature parity implementation.
Users can now find complete information about packaging, uploading,
and enhancing skills for any platform.
Related: Feature parity implementation (commits 891ce2d, 2ec2840)