docs: add proxmox-backup service description

docs/proxmox-backup/description.rst

@@ -0,0 +1,7 @@
+This daemon exposes the Proxmox Backup Server management API on
+``127.0.0.1:82``. It runs as ``root`` and has permission to do all
+privileged operations.
+
+NOTE: The daemon listens to a local address only, so you cannot access
+it from outside. The ``proxmox-backup-proxy`` daemon exposes the API
+to the outside world.

docs/proxmox-backup/man1.rst

@@ -0,0 +1,41 @@
+==========================
+proxmox-backup
+==========================
+
+.. include:: ../epilog.rst
+
+-------------------------------------------------------------
+Proxmox Backup Local API Server
+-------------------------------------------------------------
+
+:Author: |AUTHOR|
+:Version: Version |VERSION|
+:Manual section: 1
+
+
+Synopsis
+==========
+
+This daemon is normally started and managed as ``systemd`` service::
+
+ systemctl start proxmox-backup
+
+ systemctl stop proxmox-backup
+
+ systemctl status proxmox-backup
+
+For debugging, you can start the daemon in foreground using::
+
+ proxmox-backup-api
+
+.. NOTE:: You need to stop the service before starting the daemon in
+   foreground.
+
+
+Description
+============
+
+.. include:: description.rst
+
+
+.. include:: ../pbs-copyright.rst

docs/services.rst

@@ -6,3 +6,9 @@ Service Daemons
 
 .. include:: proxmox-backup-proxy/description.rst
 
+
+``proxmox-backup``
+~~~~~~~~~~~~~~~~~~
+
+.. include:: proxmox-backup/description.rst
+