Fixed #26020 -- Normalized header stylings in docs.

docs/ref/models/database-functions.txt

@@ -24,7 +24,7 @@ allows the field to have two "empty values", but it's important for the
 ``Coalesce`` example below.
 
 Coalesce
---------
+========
 
 .. class:: Coalesce(*expressions, **extra)
 
@@ -65,7 +65,7 @@ Usage examples::
     >>> Coalesce('updated', now_sql)
 
 Concat
-------
+======
 
 .. class:: Concat(*expressions, **extra)
 
@@ -92,7 +92,7 @@ Usage example::
     Margaret Smith (Maggie)
 
 Greatest
---------
+========
 
 .. class:: Greatest(*expressions, **extra)
 
@@ -136,7 +136,7 @@ and ``comment.modified``.
     a sensible minimum value to provide as a default.
 
 Least
------
+=====
 
 .. class:: Least(*expressions, **extra)
 
@@ -160,7 +160,7 @@ will result in a database error.
     a sensible maximum value to provide as a default.
 
 Length
-------
+======
 
 .. class:: Length(expression, **extra)
 
@@ -191,7 +191,7 @@ It can also be registered as a transform. For example::
     The ability to register the function as a transform was added.
 
 Lower
-------
+=====
 
 .. class:: Lower(expression, **extra)
 
@@ -213,7 +213,7 @@ Usage example::
     The ability to register the function as a transform was added.
 
 Now
----
+===
 
 .. class:: Now()
 
@@ -236,7 +236,7 @@ Usage example::
     timestamp, use :class:`django.contrib.postgres.functions.TransactionNow`.
 
 Substr
-------
+======
 
 .. class:: Substr(expression, pos, length=None, **extra)
 
@@ -255,7 +255,7 @@ Usage example::
     marga
 
 Upper
-------
+=====
 
 .. class:: Upper(expression, **extra)