Add some missing blank lines above headers in docs

docs/index.rst

@@ -4,6 +4,7 @@ django-model-utils
 
 Django model mixins and utilities.
 
+
 Contents
 ========
 
@@ -13,6 +14,7 @@ Contents
    setup
    usage
 
+
 Contributing
 ============
 

docs/setup.rst

@@ -13,6 +13,7 @@ To use ``django-model-utils`` in your Django project, just import and
 use the utility classes described in this documentation; there is no need to
 modify your ``INSTALLED_APPS`` setting.
 
+
 Dependencies
 ============
 

docs/usage.rst

@@ -105,6 +105,7 @@ field changes:
 (A ``MonitorField`` can monitor any type of field for changes, not only a
 ``StatusField``.)
 
+
 SplitField
 ----------
 
@@ -128,6 +129,7 @@ A ``SplitField`` is easy to add to any model definition:
 ``_body_excerpt`` to store the excerpt. This field doesn't need to be
 accessed directly; see below.
 
+
 Accessing a SplitField on a model
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
@@ -179,6 +181,7 @@ paragraphs are blocks of text separated by a blank line) are taken to
 be the excerpt. This number can be customized by setting the
 ``SPLIT_DEFAULT_PARAGRAPHS`` setting.
 
+
 Models
 ======
 
@@ -190,6 +193,7 @@ An abstract base class for any model that expresses a time-range. Adds
 manager that returns only objects for whom the current date-time lies
 within their time range.
 
+
 StatusModel
 -----------
 
@@ -221,6 +225,7 @@ returns objects with that status only:
     # this query will only return published articles:
     Article.published.all()
 
+
 Model Managers
 ==============
 
@@ -302,6 +307,7 @@ TimeStampedModel
 This abstract base class just provides self-updating ``created`` and
 ``modified`` fields on any model that inherits from it.
 
+
 QueryManager
 ------------