[Feature Request] support for HTTP proxy

[ccll]

Thank you for this great plugin, this is the best markdown converter I have ever used with Obsidian, simple, fast, reliable!

But I'm in area where Internet connections are not always reliable, for some websites I need to use HTTP proxy to access.
For now I need to toggle the system global proxy for slurp to work on those websites, it works but not very convenient.

It would be great if slurp allow users to set a HTTP proxy in the config.