Support post revisions #95
Description
(Note: this is all TBD - we need to consider how this will be represented in the database)
Example of post revisions in use today: https://playfulprogramming.com/posts/ffg-fundamentals-derived-values
When a post revision is created, it should have a new slug as well as an incremented "version" property in the frontmatter.
There should be an "originalPostSlug" property (name TBD) that always contains the slug of the first version of the post.
If "original_post_slug" is a column on the posts table, it could be set for all revisions in the sync-post task. This should mean that each post and its revisions can be obtained in one db query.