Add prefix "$" for command examples

This commit adds "$" for command examples as a prefix and aligns indent.

Change-Id: I7f2f2e4d8caa68e9e053b6af552911904f1aa8f8
diff --git a/README.rst b/README.rst
index 3c0463b..f1dac1c 100644
--- a/README.rst
+++ b/README.rst
@@ -92,18 +92,18 @@
    be done using the :ref:`tempest_run` command. This can be done by either
    running::
 
-     $ tempest run
+    $ tempest run
 
    from the Tempest workspace directory. Or you can use the ``--workspace``
    argument to run in the workspace you created regarless of your current
    working directory. For example::
 
-     $ tempest run --workspace cloud-01
+    $ tempest run --workspace cloud-01
 
    There is also the option to use testr directly, or any `testr`_ based test
    runner, like `ostestr`_. For example, from the workspace dir run::
 
-     $ ostestr --regex '(?!.*\[.*\bslow\b.*\])(^tempest\.(api|scenario))'
+    $ ostestr --regex '(?!.*\[.*\bslow\b.*\])(^tempest\.(api|scenario))'
 
    will run the same set of tests as the default gate jobs.
 
@@ -161,9 +161,9 @@
 of the configuration.
 
 You can generate a new sample tempest.conf file, run the following
-command from the top level of the Tempest directory:
+command from the top level of the Tempest directory::
 
-  tox -egenconfig
+    $ tox -egenconfig
 
 The most important pieces that are needed are the user ids, openstack
 endpoint, and basic flavors and images needed to run tests.
@@ -257,11 +257,11 @@
 and run the tests or use tox to do the same. Tox also contains several existing
 job configurations. For example::
 
-   $ tox -efull
+    $ tox -efull
 
 which will run the same set of tests as the OpenStack gate. (it's exactly how
 the gate invokes Tempest) Or::
 
-  $ tox -esmoke
+    $ tox -esmoke
 
 to run the tests tagged as smoke.