Allow publishers to set a list of redirect rules for their publication.
Create a system that works similarly to Ghost's. Add a collectionredirects table:
When a page isn't found, look up the from fields and see if any match. If so, redirect by 301 or 302, depending on the permanent bool value.
Users should have a way to add redirects in the admin panel. To start, they'll get access to a JSON input field. To populate this field, we'll query collectionredirects and display the JSON. When saving this data, we'll parse the JSON and then update the database.
This will be addressed in T889: UI for editing custom redirects.