Add types

[tylerodonnell]

This PR adds a index.d.ts file to be used for typescript.

[vscerchia]

Is there any reason for the namespace here?

[tylerodonnell]

I had to use a namespace so we're able to use a namespace import

import * as Authentic from "@articulate/authentic";

This allows users to still be able to do

import * as Authentic from "@articulate/authentic"
Authentic() // function
Authentic.JWT // interface

import authentic from "@articulate/authentic"
authentic() // function

import { JWT } from "@articulate/authentic"
JWT // interface

[tylerodonnell]

Without the namespace, you'll get an error in typscript: Cannot invoke an expression whose type lacks a call signature.

[vscerchia]

Left one question, but I think this looks good otherwise.

Not sure if you saw this, but I found this template on the typescript site: https://www.typescriptlang.org/docs/handbook/declaration-files/templates/module-function-d-ts.html which I think would be want we want here except for the fact that we're exporting the function using module.exports instead of export = . This seems like a good first pass, though, since I don't think we're interested in changing the actual code if we can avoid it right now.

[tylerodonnell]

@vscerchia Yeah I'm trying to leave the code alone with this PR. I'd love to make that suggestion in another version 👍