update readme

Author: zkochan

config/nerf-dart/nerf-dart.docs.mdx

@@ -9,3 +9,5 @@ import { nerfDart } from 'nerf-dart'
 nerfDart('http://registry.npmjs.org')
 //> //registry.npmjs.org/
 ```
+
+Originally from npm. Taken from <https://github.com/npm/cli/blob/latest/workspaces/config/lib/nerf-dart.js> and made available as a standalone package for easier reuse.