Add a web 'url' to .aider.conf.yml and always load a specific file.

[tuanlv14]

Issue

I saw a new feature 'Add file: CONVENTIONS.md to .aider.conf.yml to always load a specific file. I think aider also should have this kind of feature for web to save time when user try to re-use reference link in more than one time.

Version and model info

Aider v.0.46.0