Add support for Google Gemini API

[dnakov]

Checklist

• Closing issues: Add support for the Gemini API #23
• Mark this if you consider it ready to merge
• I've added tests (optional)
• I wrote some documentation

[trufae]

Sadly cant use the api from europe :___ thats why i was suggesting the other unofficial api which uses the cookies from the browser. But i think this is getting too much bloated and maybe we should start to think about defining an interface for plugins, so we can write each local/remote model on a separate file

[dnakov]

You're not missing much, 1.5 is limited to 2 req/min, basically unusable. And yeah, Inwas thinking the same thing, time for some refactoring.

[dnakov]

I'll try the cookies way, wanted to get the API one out since i had it halfway there