docs: fix syntax highlighting of code blocks

And various other cleanups

Change-Id: I240badc5358c09f006c2a22d4706ce373f2dd188
diff --git a/docs/release-notes/release-notes-0.5.0.rst b/docs/release-notes/release-notes-0.5.0.rst
index c1a8fb6..48eaf26 100644
--- a/docs/release-notes/release-notes-0.5.0.rst
+++ b/docs/release-notes/release-notes-0.5.0.rst
@@ -14,7 +14,7 @@
    compiled on such systems, but requires separate installation of a newer version of the compiler
    (e.g., clang-3.4) and dependencies.
 
-Changes since version 0.4.1
+Changes since version 0.4.1:
 
 New features
 ^^^^^^^^^^^^
@@ -105,8 +105,8 @@
 - ``StrategyInfoHost::getOrCreateStrategyInfo``, which is renamed to
   ``StrategyInfoHost::insertStrategyInfo`` (:issue:`3205`)
 
-Deletions
-^^^^^^^^^
+Removals
+^^^^^^^^
 
 - Previously deprecated BroadcastStrategy (:issue:`3206`)