docs: fix syntax highlighting of code blocks

And various other cleanups

Change-Id: I240badc5358c09f006c2a22d4706ce373f2dd188
diff --git a/docs/release-notes/release-notes-0.6.1.rst b/docs/release-notes/release-notes-0.6.1.rst
index 9339172..7295b83 100644
--- a/docs/release-notes/release-notes-0.6.1.rst
+++ b/docs/release-notes/release-notes-0.6.1.rst
@@ -3,8 +3,8 @@
 
 Release date: February 19, 2018
 
-New features:
-^^^^^^^^^^^^^
+New features
+^^^^^^^^^^^^
 
 - (potentially breaking change) ``nfd-status-http-server`` now requires Python 3