docs: update references to specific pages (#1131)

I noticed that the link was taking the reader to the main index page.
Change the links to be more specific to target the actual pages in question.

Signed-off-by: Mike Fiedler <[email protected]>

Signed-off-by: Mike Fiedler <[email protected]>

Author: miketheman

source/guides/making-a-pypi-friendly-readme.rst

@@ -97,7 +97,7 @@ If your README is written in reStructuredText, any invalid markup will prevent
 it from rendering, causing PyPI to instead just show the README's raw source.
 
 Note that Sphinx extensions used in docstrings, such as
-:doc:`directives and roles <sphinx:usage/restructuredtext/index>`
+:doc:`directives <sphinx:usage/restructuredtext/directives>` and :doc:`roles <sphinx:usage/restructuredtext/roles>`
 (e.g., "``:py:func:`getattr```" or "``:ref:`my-reference-label```"), are not allowed here and will result in error
 messages like "``Error: Unknown interpreted text role "py:func".``".