yarn support

[bchenSyd]

the company i work with have a private npm registry so I constantly switching between public registry and the corp private one, thanks to this great tool, the process has been smooth.
I was just wondering how hard it's to update ~/.yarnrc as well

I know the syntax is different for npmrc and yarnrc file, but, that different should be that big and they are all predictable
any idea in this space? thanks