Add support for Firefox

[shermozle]

I use Firefox as my daily driver. Could you support that?

I attempted to load it manually but hit some errors. Using Install Add-on from File... doesn't see the extension in the dist directory. I think Firefox looks for an .xpi file here?

Using Deb Add-ons and then Load Temporary Add-on... and selecting manifest.json it gets me to the "Thanks for installing the Orbit extension" page but the authentication URL doesn't work.

An error has occurred

The requested redirect uri is malformed or doesn't match client redirect URI.

I'd love to run this in Firefox please! Sling me test builds if you want me to test.