Add Book Progression and validation workflow documentation

[rupsis]

Before the release of any new publication of the Book(s), a run through is needed to ensure the progress of the code compiles, produces the correct results, and the text makes sense.

This is a rather involved process, and there is some "tribal knowledge" around progression procedures.

We should document these procedures in a common location.

[hollasch]

• Set up initial state
• Commit at each listing, unless it's in an uncompilable state
• In a separate worktree, make book and image fixes
• Validate rendered images
• Validate final state against source