Correct the installation doc

The instacllation doc should provide the senlin dashboard install
in devstack method, because horizon is a core service, many
developer will install this service. And if the developer want
to develop senlin-dashboard there is no doc instruction to guide
them how to install this horizon plugin.
Besides, there is a incorrect step in the install guide.

Change-Id: I375f04cb1e2621ce59740770566692e6643add05

devstack/README.rst

@@ -4,12 +4,15 @@ Enabling senlin in DevStack
 
 1. Download DevStack::
 
-     git clone https://git.openstack.org/openstack-dev/devstack
-     cd devstack
+     $ git clone https://git.openstack.org/openstack-dev/devstack
+     $ cd devstack
 
-2. Add this repo as an external repository into your ``local.conf`` file::
+2. Add following repo as external repositories into your ``local.conf`` file::
 
      [[local|localrc]]
+     #Enable senlin
      enable_plugin senlin https://git.openstack.org/openstack/senlin
+     #Enable senlin-dashboard
+     enable_plugin senlin-dashboard https://git.openstack.org/openstack/senlin-dashboard
 
-3. Run ``stack.sh``.
+3. Run ``./stack.sh``.

doc/source/install.rst

@@ -33,14 +33,17 @@ following detailed instructions.
     $ git clone https://git.openstack.org/openstack-dev/devstack
     $ cd devstack
 
-2. Add this repo as an external repository into your ``local.conf`` file::
+2. Add following repo as external repositories into your ``local.conf`` file::
 
     [[local|localrc]]
+    #Enable senlin
     enable_plugin senlin https://git.openstack.org/openstack/senlin
+    #Enable senlin-dashboard
+    enable_plugin senlin-dashboard https://git.openstack.org/openstack/senlin-dashboard
 
-3. Run ``stack.sh``::
+3. Run ``./stack.sh``::
 
-    $ stack.sh
+    $ ./stack.sh
 
 Note that Senlin client is also installed when following the instructions.