docs: remove more unmaintained/redundant entries, replace hashids with sqids

Dead/unmaintained:
- elpy (maintainer stepped down, superseded by Eglot)
- jedi-vim (superseded by native LSP clients)
- python-mode (no plugin development, only CI commits)
- fpp/PathPicker (abandoned by Facebook, last release 2022)
- mouse (last release 2020, pynput covers it)
- karateclub (last release Dec 2022)

Redundant/too niche:
- taskflow (OpenStack-internal, 372 stars)
- django-pipeline (overlaps django-compressor)
- hermescache (~1k downloads/week, solo maintainer)
- pylibmc (last release 2022, pymemcache has taken over)

Replaced:
- hashids -> sqids (hashids project rebranded, dead since 2020)

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>