Change publisher to Nix org and verify

[uncenter]

It's a shame that this extension isn't the most popular/downloaded extension in VSCode.

I think changing the publisher from @jnoortheen's personal account to a Nix organization account and verifying the Nix organization account as an official publisher (gives the extension a blue checkmark) will help with boosting the popularity of this extension. I'd also like to second #306 here, I think that will clarify this extension's "official-ness" even further.

[jnoortheen]

I am interested in moving it to the org. I am not sure, it is possible to move the extension; rather we would deprecate the current one and create a new one in place.

[uncenter]

There is some info at https://code.visualstudio.com/api/working-with-extensions/publishing-extension#deprecating-extensions. Looks like we would: change the publisher name here, publish the new extension under the org, get the old one deprecated and hopefully pointing to the new one.