docs: renamed titles

docs/extensions/index.rst

@@ -1,6 +1,6 @@
 
-Red Mail Extensions
-===================
+Extensions
+==========
 
 This section covers Red Mail's extensions. Extensions are 
 tools that helps to integrate the email sender to other 

docs/extensions/logging.rst

@@ -1,7 +1,7 @@
 
 
-Email Logging with Red Mail
-===========================
+Email Logging
+=============
 
 Red Mail also provides logging handlers which
 extends the :stdlib:`logging library's <logging.html>`