npm module

[karimmedusa]

same as emulatetab add plusastab in npm !

[joelpurra]

@karimmedusa: have planned to upgrade the PlusAsTab package to the same level as EmulateTab (automated testing, syntax checking, more package managers) quite a while now, but it's not a priority of mine. Pull requests are of course welcome! (Just know that I'll probably be super picky about the quality of all the little details.)

I'll keep this issue open until there's an NPM package.