landlock: Add user and kernel documentation

This documentation can be built with the Sphinx framework.

Cc: James Morris <jmorris@namei.org>
Cc: Jann Horn <jannh@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Serge E. Hallyn <serge@hallyn.com>
Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com>
Reviewed-by: Vincent Dagonneau <vincent.dagonneau@ssi.gouv.fr>
Link: https://lore.kernel.org/r/20210316204252.427806-13-mic@digikod.net
Signed-off-by: James Morris <jamorris@linux.microsoft.com>
5 files changed