make-doc: add an 'assets' make target for the doc
used by the swh-docs to generate images and schemas when building the whole documentation.
Depends on D649
Migrated from D651 (view on Phabricator)
Staging instance, all changes can be removed at any time
used by the swh-docs to generate images and schemas when building the whole documentation.
Depends on D649
Migrated from D651 (view on Phabricator)