[enhancement] Introduce timeout options

[doctordesh]

First, fantastic mode! I would like to donate a coffee/beer or something. Possible?

It would be awesome with an option to set the timeout of the request. I've developed against a software that had some locking issues, where the server would just not respond. And yes, I see it in the window that I didn't get a response because the time is not updated. But it's not that clear.

Would be cool to be able to set the timeout for a request, or for the whole file or something similar.

GET /thing-that-takes-time
--timeout: 5

I see that you use url-retrieve as a foundation, and I found this: https://www.gnu.org/software/emacs/manual/html_mono/url.html#index-url_002dretrieve_002dsynchronously. Maybe it would be possible to switch the the synchronous version and wrap the asynchronous nature into something else (I know close to no elisp, I don't know what I'm talking about, just thinking out loud).

Thanks for a an awesome mode!

[acgollapalli]

I'd be willing to give this a shot.