When goose makes a web request, hint to the server that markdown is preferred

[simonsickle]

Please explain the motivation behind the feature request.
I’d like goose to hint to web servers that it prefers markdown, but will also take other content types. This is helpful when requesting / reading docs and is much more token efficient than the agent reading HTML/JS/CSS

Describe the solution you'd like
Simply adding Accepts: text/markdown to outgoing requests would be sufficient.

Additional context

https://x.com/bcherny/status/1988860326306087102?s=46

• I have verified this does not duplicate an existing feature request