Re restore

Based on #10. Can now restore a piece of content. The revision fields and last modified timestamps are updated automatically.

A caveat is that you may find yourself having to modify the required fields in Composer to be able to publish the content again.

The API URL is still hardcoded. Let's have a chat about how to solve that in a way we're happy with.
Another option would be to have an endpoint that will return the config as JSON and let the backend determine which environment we're in. The security question is the same there though.