Add TypeScript support

[Calamari]

I guess, that will be a version 3, since I think there will be some opportunities to make the API a bit better. Let's see.

[Calamari]

Here it is: #57

I will play around with it a bit, before creating a new version, to see what can be optimized. Feedback is welcome, if someone dares to check it out :-)

[MikalDev]

Just FYI - testing out the typescript branch to integrate into our game.

The one thing I am going to look at adding is some stack nodes:
PushToStack(item, stackVar)
PopFromStack(stack, itemVar)
IsEmpty(stack)

(Reference: https://www.gamedeveloper.com/programming/behavior-trees-for-ai-how-they-work)