Remove ar, de, fa, ru, tr, zh documentation folders.
Update docs/index.md and docs/bg/index.md to only list en/bg.
Update README badge from 7 to 2 languages.
Update changelog entry for Bulgarian docs.
- Add mcp.md to: bg, fa, ru, tr, zh, ar
- Add index.md to Bulgarian (bg)
- Add 24 missing German (de) documentation files
Translations for all supported languages now complete.