Add definition to DefinitelyTyped

[xperiments]

Hi,

Can you please add your def to https://github.com/borisyankov/DefinitelyTyped ?

I am using your def together with my pixi def in DefinitelyTyped ( I will update it to 2.0 soon ).

Thx for your time ;-)

[alaa-eddine]

Hi @xperiments I planed this for a while, but since the modification in spine runtimes licence I'm not sure if I'm allowed to maintain the TS package :/ (I purchased spine btw but the new licence rules are unclear to me)
the current version was not modified for a while not sure if it's still up to date.

I'll push the current .d.ts to definitelyTyped.