Add contributors github handle in the about window.

[ritz078]

You can import the information from https://github.com/ritz078/moose/blob/master/.all-contributorsrc

We can use https://github.com/sindresorhus/electron-util#showaboutwindowoptions to show the about window and in the place of custom info we can add the list of contributors.

We already use the electron-util package

moose/main/modules/menu.ts

Line 2 in 89f49cd

import { appMenu, is } from "electron-util";

[purple-monke]

On it and will get it done.