Add .d.ts File for Typescript Support

[dkleber89]

Hi,

i have added some .d.ts File for Typscript Support for the Lib.

I create die Typescript definition because i want to use this lib in my Project. Maybe it´s interesting for u to integrate this direcly in the lib

This is the first shot of this declaration file and i have only loosely tested.

Are u interested? Otherwise i will close this PR

[roccomuso]

I'll leave this open but for now I don't have time to test/review this myself