Add doc for subscription cli

Add doc for subscription cli in python-zaqarclient.

Change-Id: I96edb8dd4a23dc01dad1f6fa641806bdc12cca22

doc/source/command-line.rst

@@ -18,3 +18,4 @@ Click the Link below for the details.
    command/flavor
    command/ping
    command/health
+   command/subscription

doc/source/command/subscription.rst

@@ -0,0 +1,146 @@
+Subscription
+============
+
+For help on a specific :command:`openstack subscription` command, enter:
+
+.. code-block:: console
+
+   $ openstack subscription COMMAND -h/--help
+
+The five commands:
+
+.. code-block:: console
+
+      subscription create
+      subscription delete
+      subscription list
+      subscription show
+      subscription update
+
+.. _openstack_subscription_create:
+
+openstack subscription create
+-----------------------------
+
+.. code-block:: console
+
+   usage: openstack subscription create [-h] [-f {json,shell,table,value,yaml}]
+                                        [-c COLUMN] [--max-width <integer>]
+                                        [--noindent] [--prefix PREFIX]
+                                        [--options <options>]
+                                        <queue_name> <subscriber> <ttl>
+
+Create a subscription.
+
+**Positional arguments:**
+
+``<queue_name>``
+  Name of the queue.
+
+``<subscriber>``
+  Subscriber which will be notified.
+
+``<ttl>``
+  Time to live of the subscription in seconds.
+
+
+.. _openstack_subscription_delete:
+
+openstack subscription delete
+-----------------------------
+
+.. code-block:: console
+
+   usage: openstack subscription delete [-h] <queue_name> <subscription_id>
+
+Delete a subscription.
+
+**Positional arguments:**
+
+``<queue_name>``
+  Name of the queue.
+
+``<subscription_id>``
+  ID of the subscription.
+
+
+.. _openstack_subscription_list:
+
+openstack subscription list
+---------------------------
+
+.. code-block:: console
+
+   usage: openstack subscription list [-h] [-f {csv,json,table,value,yaml}]
+                                      [-c COLUMN] [--max-width <integer>]
+                                      [--noindent]
+                                      [--quote {all,minimal,none,nonnumeric}]
+                                      [--marker <subscription_id>]
+                                      [--limit <limit>] [--detailed <detailed>]
+                                      <queue_name>
+
+Get list of subscriptions.
+
+**Positional arguments:**
+
+``<queue_name>``
+  Name of the queue.
+
+
+.. _openstack_subscription_show:
+
+openstack subscription show
+---------------------------
+
+.. code-block:: console
+
+   usage: openstack subscription show [-h] [-f {json,shell,table,value,yaml}]
+                                      [-c COLUMN] [--max-width <integer>]
+                                      [--noindent] [--prefix PREFIX]
+                                      <queue_name> <subscription_id>
+
+Query a subscription details.
+
+**Positional arguments:**
+
+``<queue_name>``
+  Name of the queue.
+
+``<subscription_id>``
+  ID of the subscription.
+
+
+.. _openstack_subscription_update:
+
+openstack subscription update
+-----------------------------
+
+.. code-block:: console
+
+   usage: openstack subscription update [-h] [-f {json,shell,table,value,yaml}]
+                                        [-c COLUMN] [--max-width <integer>]
+                                        [--noindent] [--prefix PREFIX]
+                                        [--subscriber <subscriber>] [--ttl <ttl>]
+                                        [--options <options>]
+                                        <queue_name> <subscription_id>
+
+Update a subscription.
+
+**Positional arguments:**
+
+``<queue_name>``
+  Name of the queue.
+
+``<subscription_id>``
+  ID of the subscription
+
+**Optional arguments:**
+
+``--subscriber <subscriber>``
+   Subscriber which will be notified.
+
+``--ttl <ttl>``
+  Time to live of the subscription in seconds.
+
+``--options <options>``
+  Metadata of the subscription in JSON format.