Refactor ONOS helm doc

Change-Id: Id89ef59542dfaa4fc15610d15d5d627771ff0b16
diff --git a/mdl_relaxed.rb b/mdl_relaxed.rb
index 9448317..92e3fe8 100644
--- a/mdl_relaxed.rb
+++ b/mdl_relaxed.rb
@@ -46,3 +46,5 @@
 # Exclude rule: Fenced code blocks should be surrounded by blank lines
 exclude_rule 'MD031'
 
+# Exclude rule: Emphasis used instead of a header
+exclude_rule 'MD036'