[WIP] add typescript definitions

[clhenrick]

to resolve #2

[clhenrick]

@Fil I need to test this out still, so not ready to merge yet.

[clhenrick]

Seems to work for me when I import this branch into a Typescript project:

import versor = require("versor");

const v0 = versor([ 0, 0, 0 ]);
const v1 = versor([ 90, 0, 0 ]);

const delta = versor.delta(v0, v1);

const delta2 = versor.delta(v0, v1, 0.5);

const cartesian = versor.cartesian([-80, 44]);

const rotation = versor.rotation([10, 30, 40, 4]);

const multiply = versor.multiply([10, 20, 30, 40], [0, 20, 30, 50]);

// typescript yells at this for example
versor.delta("a", "b");

// it also yells about this
versor("a");

// and this
versor.multiply([0, 1, 2]);

[clhenrick]

in Typescript if you use the import * as versor from "versor" method then you need to use versor.default() to do the equivalent of versor() as when using common js var versor = require("versor").