Allow GitHub contributors to mint an NFT

This guide shows you how to create an app where users can sign in with their GitHub and web3 wallet. Once they are signed in, we will validate if they have contributed to one of our repos. If you already have a Next.js app you can simply follow these steps to get started. Follow Github's Creating a personal access token guide and add this as an environment variable in your project. We'll use this to make requests to GitHub's API without getting rate-limited.