[1.8.x] Corrected some inconsistent headings in docs/ref/templates/builtins.txt.

Backport of 7080cef7bf from master

docs/ref/templates/builtins.txt

@@ -389,7 +389,7 @@ clauses, as well as an ``{% else %}`` clause that will be displayed if all
 previous conditions fail. These clauses are optional.
 
 Boolean operators
-^^^^^^^^^^^^^^^^^
+"""""""""""""""""
 
 :ttag:`if` tags may use ``and``, ``or`` or ``not`` to test a number of
 variables or to negate a given variable::
@@ -431,9 +431,8 @@ them to indicate precedence, you should use nested :ttag:`if` tags.
 :ttag:`if` tags may also use the operators ``==``, ``!=``, ``<``, ``>``,
 ``<=``, ``>=`` and ``in`` which work as follows:
 
-
 ``==`` operator
-^^^^^^^^^^^^^^^
+~~~~~~~~~~~~~~~
 
 Equality. Example::
 
@@ -442,7 +441,7 @@ Equality. Example::
     {% endif %}
 
 ``!=`` operator
-^^^^^^^^^^^^^^^
+~~~~~~~~~~~~~~~
 
 Inequality. Example::
 
@@ -452,7 +451,7 @@ Inequality. Example::
     {% endif %}
 
 ``<`` operator
-^^^^^^^^^^^^^^
+~~~~~~~~~~~~~~
 
 Less than. Example::
 
@@ -461,7 +460,7 @@ Less than. Example::
     {% endif %}
 
 ``>`` operator
-^^^^^^^^^^^^^^
+~~~~~~~~~~~~~~
 
 Greater than. Example::
 
@@ -470,7 +469,7 @@ Greater than. Example::
     {% endif %}
 
 ``<=`` operator
-^^^^^^^^^^^^^^^
+~~~~~~~~~~~~~~~
 
 Less than or equal to. Example::
 
@@ -479,7 +478,7 @@ Less than or equal to. Example::
     {% endif %}
 
 ``>=`` operator
-^^^^^^^^^^^^^^^
+~~~~~~~~~~~~~~~
 
 Greater than or equal to. Example::
 
@@ -488,7 +487,7 @@ Greater than or equal to. Example::
     {% endif %}
 
 ``in`` operator
-^^^^^^^^^^^^^^^
+~~~~~~~~~~~~~~~
 
 Contained within. This operator is supported by many Python containers to test
 whether the given value is in the container. The following are some examples
@@ -509,11 +508,10 @@ of how ``x in y`` will be interpreted::
     {% endif %}
 
 ``not in`` operator
-^^^^^^^^^^^^^^^^^^^
+~~~~~~~~~~~~~~~~~~~
 
 Not contained within. This is the negation of the ``in`` operator.
 
-
 The comparison operators cannot be 'chained' like in Python or in mathematical
 notation. For example, instead of using::
 
@@ -523,9 +521,8 @@ you should use::
 
     {% if a > b and b > c %}
 
-
 Filters
-^^^^^^^
+"""""""
 
 You can also use filters in the :ttag:`if` expression. For example::
 
@@ -534,7 +531,7 @@ You can also use filters in the :ttag:`if` expression. For example::
     {% endif %}
 
 Complex expressions
-^^^^^^^^^^^^^^^^^^^
+"""""""""""""""""""
 
 All of the above can be combined to form complex expressions. For such
 expressions, it can be important to know how the operators are grouped when the
@@ -564,7 +561,6 @@ If you need different precedence, you will need to use nested :ttag:`if` tags.
 Sometimes that is better for clarity anyway, for the sake of those who do not
 know the precedence rules.
 
-
 .. templatetag:: ifchanged
 
 ifchanged
@@ -808,7 +804,6 @@ This would display as "It is the 4th of September".
 
         It is {% now "SHORT_DATETIME_FORMAT" %}
 
-
 You can also use the syntax ``{% now "Y" as current_year %}`` to store the
 output (as a string) inside a variable. This is useful if you want to use
 ``{% now %}`` inside a template tag like :ttag:`blocktrans` for example::
@@ -827,7 +822,9 @@ regroup
 
 Regroups a list of alike objects by a common attribute.
 
-This complex tag is best illustrated by way of an example: say that "places" is a list of cities represented by dictionaries containing ``"name"``, ``"population"``, and ``"country"`` keys:
+This complex tag is best illustrated by way of an example: say that "places" is
+a list of cities represented by dictionaries containing ``"name"``,
+``"population"``, and ``"country"`` keys:
 
 .. code-block:: python
 
@@ -839,7 +836,8 @@ This complex tag is best illustrated by way of an example: say that "places" is
         {'name': 'Tokyo', 'population': '33,000,000', 'country': 'Japan'},
     ]
 
-...and you'd like to display a hierarchical list that is ordered by country, like this:
+...and you'd like to display a hierarchical list that is ordered by country,
+like this:
 
 * India
 
@@ -855,7 +853,6 @@ This complex tag is best illustrated by way of an example: say that "places" is
 
   * Tokyo: 33,000,000
 
-
 You can use the ``{% regroup %}`` tag to group the list of cities by country.
 The following snippet of template code would accomplish this::
 
@@ -935,7 +932,7 @@ Another solution is to sort the data in the template using the
     {% regroup cities|dictsort:"country" by country as country_list %}
 
 Grouping on other properties
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+""""""""""""""""""""""""""""
 
 Any valid template lookup is a legal grouping attribute for the regroup
 tag, including methods, attributes, dictionary keys and list items. For
@@ -2422,8 +2419,8 @@ Django's built-in :tfilter:`escape` filter. The default value for
 urlizetrunc
 ^^^^^^^^^^^
 
-Converts URLs and email addresses into clickable links just like urlize_, but truncates URLs
-longer than the given character limit.
+Converts URLs and email addresses into clickable links just like urlize_, but
+truncates URLs longer than the given character limit.
 
 **Argument:** Number of characters that link text should be truncated to,
 including the ellipsis that's added if truncation is necessary.