qapi: Require descriptions and tagged sections to be indented

qapi: Require descriptions and tagged sections to be indented

By convention, we indent the second and subsequent lines of
descriptions and tagged sections, except for examples.

Turn this into a hard rule, and apply it to examples, too.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240216145841.2099240-11-armbru@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
[Straightforward conflicts in qapi/migration.json resolved]