txmanifest.schema.json is copied verbatim from the reference wallet:
repo: git@github.com:stringhandler/txmanifest-wallet.git
path: schema/txmanifest.schema.json
ref: main @ 5624dfc77f742d66798d469de1bb79c8f09fcf0b
format: manifest_version 0.2.0
It is generated in that repo by txmanifest_lib/examples/gen_schema.rs, so it is
the machine-readable source of truth for what a manifest may contain. The book's
JSON examples are checked against it by scripts/check_manifests.py.
To refresh it, re-copy the file and update the ref above.