Fixed #16863 -- Corrected ReST markup to avoid errors building docs.

Although directives such as "note" and "warning" will accept content
immediately following the directive, this is technically where arguments to the
directive should go (see http://sphinx.pocoo.org/rest.html#directives). Putting
the content there means that any lines beginning with an inline text role
(e.g. ":setting:`DEBUG`") will be mis-interpreted as an option block for the
directive. To avoid this error, there should always be a blank line between the
directive start and the directive content.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@16842 bcc190cf-cafb-0310-a4f2-bffc1f526a37

docs/howto/custom-model-fields.txt

@@ -177,6 +177,7 @@ below), but we ensure it has a fixed length, since it only needs to hold 52
 card values plus their suits; 104 characters in total.
 
 .. note::
+
     Many of Django's model fields accept options that they don't do anything
     with. For example, you can pass both
     :attr:`~django.db.models.Field.editable` and
@@ -189,8 +190,8 @@ card values plus their suits; 104 characters in total.
     This behavior simplifies the field classes, because they don't need to
     check for options that aren't necessary. They just pass all the options to
     the parent class and then don't use them later on. It's up to you whether
-    you want your fields to be more strict about the options they select, or
-    to use the simpler, more permissive behavior of the current fields.
+    you want your fields to be more strict about the options they select, or to
+    use the simpler, more permissive behavior of the current fields.
 
 .. method:: Field.__init__