docs: update README
feat: prompt user to renew token if expired
style: change icons
fix: adjust version number
build: organized code according to setuptools
style: apply black coding style and ruff linter
feat: inhibit shutdown while sync is in progress
refactor: Use proper private prefix on DeleteDialog
feat: delete files during bisync if the user specified so
feat: show a custom error when sync failed due to delete

The dialog doesn't do anything yet though.
feat: show a friendlier last sync datetime
refactor: remove wrong code preventing token expiry
fix: dont break if the development flag is not set
feat: changed the approach to use bisync instead of mount
feat: add quit menu item
feat: add custom tasks defined in the toml file