docs: renamed titles

docs/tutorials/jinja_support.rst

@@ -4,8 +4,8 @@
 
 .. _jinja-support:
 
-Jinja Support
-=============
+Jinja Templating
+================
 
 Red Mail uses Jinja for templating the HTML and text 
 bodies. This enables a lot of features out-of-the box.

docs/tutorials/templating.rst

@@ -5,8 +5,8 @@
 
 .. _templating:
 
-Setting Jinja Environments
-==========================
+Jinja Environments
+==================
 
 There are two ways of setting a custom Jinja env
 to Red Mail: from paths or directly setting the