Write spec for version control

[MaggieAppleton]

Final Spec: Specs/VersionControl.md

Concept

Macro content on the garden can have new versions added to it.

Versions are not created automatically every time you edit a post. Authors need to explicitly decide a piece has changed enough to warrant a new version.

Older versions should still be preserved, and any links to them should still work.

Each piece of content still needs to have a canonical link. E.g. bob.com/quantum-physics This link should ideally always go to the latest version. If it links to a previous version, there should be a clearly visible banner / element on the page that says this is an old version, and links people to the latest version.

Use redirects to always sends users to the latest version. We can forward people from the canonical link to the latest. E.g. bob.com/quantum-physics -> bob.com/quantum-physics/v2 or bob.com/quantum-physics/v3

We expect most posts won't have version. Posts without versions simply live on their canonical URLs. Once a post has two versions, we add v1 and v2 to the end of the URL

So bob.com/quantum-physics becomes bob.com/quantum-physics/v1 and bob.com/quantum-physics/v2 The canonical URL now forwards people to the latest version. This decision is based on the assumption authors usually want people to read the latest version. Readers can still view and directly link to v1, but the default URL redirects to v2

Requirements

Authors must be able to:

• Create new versions of content
• Keep old versions without worrying about losing them
• Link to both old and new versions

Readers must be able to:

• View previous versions of content
• Know what version they're currently looking at
• Easily navigate to previous versions via a version sidebar or similar
• (??) See a diff of what's changed between the two versions