* Drop support for Python < 3.7
* Support cache customization with OpenSlide 3.5.0
* Improve pixel read performance
* Clarify exception raised on Windows or macOS when OpenSlide can't be found
* Raise `OpenSlideVersionError` when an operation requires a newer OpenSlide
* Support `pathlib.Path` in filename arguments
* Fix Pillow `Image.ANTIALIAS` deprecation warning
* docs: Add detailed installation instructions
* docs: Convert `README` and `CHANGELOG` to Markdown
* examples: Share cache among all multiserver slides, if supported
* examples: Fix `deepzoom_tile.py --viewer` with Jinja 3.x
* examples: Read OpenSlide DLL path from `OPENSLIDE_PATH` env var on Windows
* examples: Update OpenSeadragon to 3.0.0