Now that various new API have been added or are coming soon, it is
worth a landing page that gives an overview of capturing various
pieces of guest state, and which APIs are best suited to which tasks.
Signed-off-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NJohn Ferlan <jferlan@redhat.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>

The previously added AMD SEV doc was not linked from anywhere on the
website. Address this by introducing a new "Knowledge base" section
that can hold task oriented guide to various features. Moving the SEV,
disk locking and secure usage guides under this section.
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>