Location of the "local.conf" file is confusing. It is updated.

It was shown that the local.conf is at root devstack directory, but
it is at devstack/samples directory. So the path is updated.

1.) Copy the file into root Devstack directory.

Change-Id: I6ff8a404a3664c892bb458023c57ccc5d0926fdf
Closes-Bug: #1464491
diff --git a/doc/source/configuration.rst b/doc/source/configuration.rst
index 05a8d95..90b7d44 100644
--- a/doc/source/configuration.rst
+++ b/doc/source/configuration.rst
@@ -28,8 +28,10 @@
 local.conf
 ==========
 
-The new configuration file is ``local.conf`` and resides in the root
-DevStack directory like the old ``localrc`` file. It is a modified INI
+The new configuration file is ``local.conf`` and should reside in the
+root Devstack directory. An example of such ``local.conf`` file
+is provided in the ``devstack/samples`` directory. Copy this file into
+the root Devstack directory and adapt it to your needs. It is a modified INI
 format file that introduces a meta-section header to carry additional
 information regarding the configuration files to be changed.