Fixing rst of tempest readme

Change-Id: Ib337b23fe07e4f8114154cd4dd4558a9d533606d

almanach/tests/tempest/README.rst

@@ -10,6 +10,7 @@ Tempest Configuration File
 Example of config file for devstack:
 
 .. code:: bash
+
     [DEFAULT]
 
     [identity]
@@ -37,6 +38,13 @@ Run tests on your local machine
     - :code:`testr run`
     - :code:`tempest run`
 
+Note: you can overwrite the default folder of the configuration by setting two environment variables
+
+.. code:: bash
+
+    export TEMPEST_CONFIG=tempest.conf
+    export TEMPEST_CONFIG_DIR=/tmp/
+
 
 Run tests in devstack
 ---------------------