A Schema is either an Object or a boolean. We could reduce JsonSchema scope further
by adding properties, but a schema is a really complex type so its not worth the
effort.
The feature comes from the "x-deprecated" field in schemas (any schema that is used
to parse arguments), and can be a boolean or a string.
The parser now takes a logger and will warn users when encountering a deprecated
option. These options will also appear in JSON help.
--help now accepts a value which can be a boolean or a string. If the value
is not understood we simply show a message to the user that it was invalid.
SubCommands are not tied to the option that triggers them. They
contain a subset of a CommandDescription interface, with at least
a short and long description and usage notes. These are generated
from the subcommand schema (e.g. schematics in case of generate).
