4.0.0 release checklist

[benoit-pierre]

Pre:

• put Circle CI out of its misery: it will continue trying and failing even though the configuration has been removed...
• update translations (French, Spanish) (for Add translation into Spanish #1165 post release)
• clarify macOS situation: oldest supported version?
• configure PyPI token for release
• update to Python 3.8
• update requirements (taking the macOS situation into account, should address build(deps): bump bleach from 3.1.4 to 3.3.0 #1183 and build(deps): bump pygments from 2.6.1 to 2.7.4 #1192)
• review and merge Fix output capitalization issue on X #1153
• review and merge Add "Save as..." feature for dictionary conversion #1149 / Add dictionaries "save as..." support #1244 (Save As… feature)
• add Calibre-like warning to plugins manager
• do a pass on setup metadata (changelog link? switch back long description to readme contents?)
• clear 4.0.0 milestone: Include libusb in the Mac App bundle #904 (libusb), Document the plugins system #912 (plugin docs), and Configuration is not saved if the only change is enabling one extension plugin #1180 (extensions config) still left
• create a RC for testing, promote to final when happy
• update AUR (git) package

Post RC/final:

• update AUR (stable) package
• add Melani plugin to registry (need new version to depend on)
• add Yawei-Steno3 plugin to registry

Possibly:

• update other Linux distributions packages
• partially merge Fix tooltip punctuation consistency (issue #963) and make tool tooltips localizable #999 (punctuation consistency only)
• review and merge Lock the display on use in KeyboardCapture for X #1163 (lock display)
• cherry pick part of Updated ortho rules for Magnum/Stanley's theory rules.. #1092
• redesign icon for Big Sur (add dumb white box around it)
• Register Plover on https://appimage.github.io #1067 (register AppImage)

[benoit-pierre]

@morinted: thoughts? Anything I missed?