docs: Document how to use custom `api_url` in Assistant (#11790)
This essentially documents the comment here:
https://github.com/zed-industries/zed/issues/4424#issuecomment-2053646583
Release Notes:
- N/A
4766b41e96Thorsten Ball committed on 5/14/2024, 9:39:57 AM· committed by GitHubparent95e0d5e