[1.2.X] Fixed #14835 -- Corrected a lack of indentation in the reST markup for...

[1.2.X] Fixed #14835 -- Corrected a lack of indentation in the reST markup for docs/ref/contrib/admin/index.txt and reflowed the text accordingly.

Thanks to cogat for the report.

Backport of [14830] from trunk - approximate, because other changes have
made it very hard to do exactly.

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.2.X@15620 bcc190cf-cafb-0310-a4f2-bffc1f526a37