TypeScript definition file

[bennycode]

To make cbor-js work with TypeScript code, it would be nice to have a TypeScript definition file (*.d.ts) for the methods cbor-js exposes:

• https://www.typescriptlang.org/docs/handbook/writing-declaration-files.html
• http://www.typescriptlang.org/docs/handbook/typings-for-npm-packages.html