I have started using Git control with Visual Studio Code. I'm releasing this as the latest working stable build.
Download the source code below, and extract it to your_gmod_server/garrysmod/addons.
Rename the file to just nadmin, otherwise it may not work. Primarily from the . in the file name. When I make the next release, I'll actually attach a proper nadmin file download that you don't really have to tinker with.