Add links to example implementations using React and Vue

[coderberry]

Feature Request

What problem does this solve

Some publishers would prefer to integrate CodeFund via React or Vue but have no idea what the best practice for doing this is.

Describe the solution you'd like

Below the instructions box, I think there should be links to different implementation examples. For example, here's a React implementation: https://codesandbox.io/s/codefund-react-example-8q75t

Describe alternatives you've considered

N/A

Additional context

Triggered by request from publisher

[andrewmcodes]

I have the react on 99% done, just needs some admin work to make it easy for everyone to use.

Hoping to find a vue expert to help me with that part.