code_style.rst: a couple of tidyups

docs/code_style.rst

-Basically, PEP8
-
+- Everything should comply with PEP8. Code should pass
+  ``pep8 --max-line-length=100`` without any warnings.
 - NEVER tabs. 4 spaces to indent.
 - Max line width: 79 chars (with flexibility to overflow by a "few chars" if
   the overflowing content is not semantically significant and avoids an
@@ -43,10 +43,10 @@ Basically, PEP8
   together, or want to deliberately extend or preserve vertical/horizontal
   space)
 
-Comments should follow the `google code style <http://google.github.io/styleguide/pyguide.html?showone=Comments#Comments>`_.
-This is so that we can generate documentation with 
-`sphinx <http://sphinxcontrib-napoleon.readthedocs.org/en/latest/>`_. See the
-`examples <http://sphinxcontrib-napoleon.readthedocs.io/en/latest/example_google.html>`_
-in the sphinx documentation.
-
-Code should pass pep8 --max-line-length=100 without any warnings.
+- Comments should follow the `google code style
+  <http://google.github.io/styleguide/pyguide.html?showone=Comments#Comments>`_.
+  This is so that we can generate documentation with `sphinx
+  <http://sphinxcontrib-napoleon.readthedocs.org/en/latest/>`_. See the
+  `examples
+  <http://sphinxcontrib-napoleon.readthedocs.io/en/latest/example_google.html>`_
+  in the sphinx documentation.