Add typescript example setup

[Naxos84]

Since PixiJS 5 typescript definitions are part of pixijs itself.

Therefor it would be really helpful if a typescript example setup would also be part of this.

I found ot so far, that the tsconfig.json nees at least "module": "commonjs". Though I'm really new to all this stuff.

If I can help with some example please let me know and I try to figure it out :D