Perq 0.2.1

Perq is now available on PyPI.

python -m pip install perq
# Optional persistent LMDB backend:
python -m pip install 'perq[lmdb]'

This documentation release updates the package page with PyPI installation instructions and fixes documentation links so they work from both GitHub and PyPI. Matching behavior and index formats are unchanged from 0.2.0.

See the README, benchmarks, and migration guide.