MAINT: update ReST formatting in README.

Related to missing README content on
https://pypi.python.org/pypi/numpydoc/0.7.0

Doesn't help fix that, but at least this file now looks like valid ReST.

Author: rgommers

README.rst

@@ -28,30 +28,30 @@ Options
 
 The following options can be set in conf.py:
 
-- numpydoc_use_plots: bool
+- ``numpydoc_use_plots``: bool
 
   Whether to produce ``plot::`` directives for Examples sections that
   contain ``import matplotlib``.
 
-- numpydoc_show_class_members: bool
+- ``numpydoc_show_class_members``: bool
 
   Whether to show all members of a class in the Methods and Attributes
   sections automatically.
   ``True`` by default.
 
-- numpydoc_show_inherited_class_members: bool
+- ``numpydoc_show_inherited_class_members``: bool
 
   Whether to show all inherited members of a class in the Methods and Attributes
   sections automatically. If it's false, inherited members won't shown.
   ``True`` by default.
 
-- numpydoc_class_members_toctree: bool
+- ``numpydoc_class_members_toctree``: bool
 
   Whether to create a Sphinx table of contents for the lists of class
   methods and attributes. If a table of contents is made, Sphinx expects
   each entry to have a separate page.
   ``True`` by default.
 
-- numpydoc_edit_link: bool  (DEPRECATED -- edit your HTML template instead)
+- ``numpydoc_edit_link``: bool  (DEPRECATED -- edit your HTML template instead)
 
   Whether to insert an edit link after docstrings.