Possible improvements: use rollup and TypeScript, add support for npm init

[diskdance]

This repo looks good, but it can be better.

I have tried writing gadgets with ES bundler (rollup) and TypeScript several times and feel comfortable with my solution overall:

1. rollup has few dependencies than browserify and is more modern for ES bundling
2. I created a rollup plugin for integration with MW ResourceLoader and can (for instance) use Vue.js from MediaWiki itself
3. TypeScript allows you to write strongly typed JavaScript and with types-mediawiki you got Intellisense for mw interfaces

It would be great if this repo can be updated and add support for npm init.