Bigger Thunderbird

Increase font sizes in Thunderbird for better readabilty.

Tested for Thunderbird 78.5.0 / MacOS 10.15.7

Installing process

1. Open the preferences in Thunderbird, find "Config editor..." at the bottom of the "General" tab
2. "Accept the risk" and search for toolkit.legacyUserProfileCustomizations.stylesheets and set this to true
3. Download the contents of this repository
4. place it in your Thunderbird profile like so:
   /Library/Thunderbird/Profiles/xxxxxxx.default/chrome/userChrome.css
5. restart Thunderbird
6. enjoy a good looking Thunderbird