It actually run only on Node (but could be adapted on browser). Yes an online demo is a good idea!
I did used prettier and Xo in the past. I know I'm in the wrong but my eye are so much adapted to that C/C# style that it is way easier for me to read. For a next update/my next open-source projects, I'll think twice about it.
I have no doubt Typescript is great. I've tried use it in previous very complex projects pushing JS to limits. It had a few quircks that made it unable to use, same thing for Flow. But same thing here, I'll think about it twice next time!
Also, you should check out the JS formatting guide (I can recommend you prettier). Your code looks like being written by an C# developer :D