Add Push to Talk toggle

[loganintech]

Adds "Toggle Push to Talk" to the actions list, and allows specifying a DISCORD_CLIENT_ID and DISCORD_CLIENT_SECRET during build time so that the installing user doesn't have to

[nekename]

If you want to remove that change and just submit the Toggle PTT action I'd be happy to review

[loganintech]

@nekename Restored the old auth code, please lmk if you'd like me to remove the flake config too.

Put the flake in #4