(feat) add OpenRouter as provider

[tobitege]

Description ✏️

Add OpenRouter as model provider.

What changed? Feel free to be brief.

• schemas/config.json: added openrouter to provider enum and corresponding entry in markdownEnumDescriptions; make apiKey required
• index.d.ts, types.ts: added openrouter to ModelProvider
• apparently my editor also removed a ton of trailing blanks

Checklist ✅

• I have added screenshots (if UI changes are present).
• I have done a self-review of my code.
• I have manually tested my code (if applicable).

It's my first time looking into this codebase, I apologize if I'm missing requirements here. 😬

[charlwillia6]

@tobitege I cannot seem to get this to work. I even manually added my configuration, and it won't except it. If you have this working on your end, can you post a screenshot, or detail the steps as to how to setup an OpenRouter configuration?

[tobitege]

Hey @charlwillia6
I'm sorry, I did the PR as a dry-run and couldn't test it live as I've got no experience with VS Code development. 😭

[tobitege]

Closing this. I don't have the time to get this working, sorry.