Adding typescript definition file

[gama410]

Hello!

Thanks for your library. It exactly fits my needs here.
I'd like to propose integrating a typescript definition file for those of us working in typescript.

Just for information, here is the code I wrote for the definition file. It should only be added to the project:

`declare module 'timespan' {
export class TimeSpan {
constructor(milliseconds: number, seconds: number, minutes: number, hours: number, days: number);
add(timeSpan: TimeSpan): void;
addMilliseconds(milliseconds: number): void;
addSeconds(seconds: number): void;
addMinutes(minutes: number): void;
addHours(hours: number): void;
addDays(days: number): void;
subtract(timeSpan: TimeSpan): void;
subtractMilliseconds(milliseconds: number): void;
subtractSeconds(seconds: number): void;
subtractMinutes(minutes: number): void;
subtractHours(hours: number): void;
subtractDays(days: number): void;
totalMilliseconds(roundDown: boolean): number;
totalSeconds(roundDown: boolean): number;
totalMinutes(roundDown: boolean): number;
totalHours(roundDown: boolean): number;
totalDays(roundDown: boolean): number;

    equals(timeSpan: TimeSpan): boolean;
    toString(): string;

    readonly milliseconds: number;
    readonly seconds: number;
    readonly minutes: number;
    readonly hours: number;
    readonly days: number;
}
export function fromMilliseconds(milliseconds: number): TimeSpan;
export function fromSeconds(seconds: number): TimeSpan;
export function fromMinutes(minutes: number): TimeSpan;
export function fromHours(hours: number): TimeSpan;
export function fromDays(days: number): TimeSpan;
export function parse(str: string): TimeSpan;
export function parseDate(str: string): Date;
export function fromDates(start: string | Date, end: string | Date, abs: boolean): TimeSpan;
export function test(str: string): boolean;
export function instanceOf(timeSpan: any): boolean;
export function clone(timeSpan: TimeSpan): TimeSpan;

}
`

And reference it in your package.json. eg:

{ "name": "awesome", "author": "Vandelay Industries", "version": "1.0.0", "main": "./lib/main.js", "types": "./lib/main.d.ts" }

Thanks!