add MaskJS

Hallo Team, thanks for the excellent CDN. I'm adding here [MaskJS](https://github.com/atmajs/maskjs) library. 
Is everything well formatted? 
I was a bit confused with:
> If you are adding a project for the first time please add only the minified version

Should I exclude the not minified file from this pr? How then it could be added to the package again? With new release only?

Cheers, Alex