Merge branch 'issue-315'

Author: IanLee1521

docs/intro.rst

@@ -185,8 +185,17 @@ Configuration
 
 The behaviour may be configured at two levels.
 
-The user settings are read from the ``~/.config/pep8`` file and
-for Windows from the ``~\.pep8`` file.
+The user settings are read from the following locations:
+
+If on Windows:
+    ``~\.pep8``
+
+Otherwise, if the :envvar:`XDG_CONFIG_HOME` environment variable is defined:
+    ``XDG_CONFIG_HOME/pep8``
+
+Else if :envvar:`XDG_CONFIG_HOME` is not defined:
+    ``~/.config/pep8``
+
 Example::
 
   [pep8]