Migrate mywebpage/bin/mywebpage CLI features into mytoolkit:
- deploy: auto-infer GIT_USER from gh CLI or git origin
- pdf build/open: delegate to project's scripts/export-docs-pdf.py
- build --serve: serve built site after successful build
- Add new subcommands: convert, preflight, server, templates, webpage
- Migrate config from bin/config.json to ~/.config/mytoolkit
- Fix expand_bookmarks to modify writer objects instead of reader
- Improve md_to_pdf with CJK bookmark support
- Update README and project metadata
Zhengshou Lai