Fixing netlifyIdentity login bug

[luczaki114]

The problem:
Sometimes the NetlifyIdentity script did not finish loading before the below script executed.

<script>
  if (window.netlifyIdentity) {
    window.netlifyIdentity.on("init", user => {
      if (!user) {
        window.netlifyIdentity.on("login", () => {
          document.location.href = "/admin/";
        });
      }
    });
  }
</script>

This script is necessary on the home page since netlifyIdentity's auth process involves sending a Json Web Token to the home page for verification, at which point you are logged in, and sent back to the admin page.

The solution:
I added a react-load-script dependency and used it to call the netlifyIdentity script and created an onLoad handler where I placed the script that needs to execute.

I also added in a manual netlifyIdentity.init() call since netlifyIdentity.js only adds itself to the window, but does not initialize.

[luczaki114]

Actually, dont merge this. I'll create a clean copy so its just one commit.