[FEATURE] Google Authentication

[SLcode777]

Feature Description

Add the possibility to signup/signin with a Google Account

Problem It Solves

For now, only people with a GitHub or GitLab account can signin.

Would you like to implement this?

• Yes, I'd like to work on this
• Yes, I can but I don't mind if somebody else does
• No, but I'd be happy to help test it
• No, just suggesting