Support for self-hosted sourcegraph instance

[Ajetski]

This plugin seems great! Thanks for the work put into this. I'm noticing that everything works fine with the cloud-based Sourcegraph Api, but not with my local instance.

I'm reading through the repo now and don't see anything in the configuration about using a different Sourcegraph endpoint. Is there an option that I've overlooked?

If this is work that needs doing, I can contribute if necessary. Thanks again!

[tjdevries]

I just pushed better support for this -- if you wanted to give it a try, I'd be happy to try and solve any bugs you run into