add typings

[RobinRadic]

Untested and far from ideal. But it should work.

fixes #59

[a21ns1g4ts]

@RobinRadic Usually we return id integer. If we can change the type to Number ?

[mesqueeb]

@a21ns1g4ts this will break a lot of the library I believe where we check for the ID and expect a string.

You could fork the library and try changing it to number, see where it works and where you need to tweak it.

PR's welcome!

[a21ns1g4ts]

So ok. I will try a practical way to get around the problem