Fix react router backpage bug

[MatthewNobes]

When going back to a previous react-router page, the application seems to get stuck and displays the error 404 page, this should be fixed.

[MatthewNobes]

The same also happens on page refresh

[MatthewNobes]

Further details on the fix can be found here: https://reginafurness.medium.com/client-side-routing-on-github-pages-with-create-react-app-f5a393341c2
With the code for this coming from the index.html and 404.html of this repo: https://github.com/rafgraph/spa-github-pages

[MatthewNobes]

Patched