Alpha 0.4.3

Version 0.4.3 should fix a bug reported in a comment on issue #4.

This version supports Dark and Darker theme variants. 🎉

If you are using Arc Dark or Arc Darker as your OS theme, you should change the styling of the integration to match the theme variant. You can switch to those variants by going to Menu > Preferences > Display > Arc Integration and tweaking the styling as you like.

As of version 0.4.0 the majority the integration is done, but it still needs more polishing.

Because this project is still in alpha state, feedback is appreciated. Due to the lack of knowledge of how things work in Thunderbird, mess-ups may be very likely, therefore everyone is welcome to report any visual bug that might be found.