Modernize repo

[leplatrem]

• Use version from git tag using cargo-edit
• Publish to Pypi on git tag
• Add config to categorize changes in autogenerated changelog
• Update release instructions
• Rename master to main
• Wait for action to be allowed (see last run on tag) https://bugzilla.mozilla.org/show_bug.cgi?id=1877222

Things lost with this PR:

• No more changelog (now on GH releases)
• No more contributors file