Fixed #13497 -- Corrected various typos and markup problems in docs. Thanks to...

Fixed #13497 -- Corrected various typos and markup problems in docs. Thanks to Ramiro Morales for the report and patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@13144 bcc190cf-cafb-0310-a4f2-bffc1f526a37