Some upstream repos still need fixes, but this gets us close enough that
style hints can be enabled by default.
In general, "canonical" spellings are preferred even if they violate
nep-1 - this applies in particular to spec-related stuff like
`genesis_validators_root` which appears throughout the codebase.
* initial auditor handbook commit
* Move in publishable state
* otu of-line comment to avoid mdbook bug
* Fix links
* Add threat model
* Update: move rocksdb and protobuf, placeholder for areas of focus