Have clang-tidy header match others

This section isn't any more important than the others.

Tested: Doc change. Pushed to fork, looked good.

Change-Id: If9e888aff92dc389183f8a53527e603d1c685ad0
Signed-off-by: Gunnar Mills <gmills@us.ibm.com>
diff --git a/DEVELOPING.md b/DEVELOPING.md
index 4a481c9..be61476 100644
--- a/DEVELOPING.md
+++ b/DEVELOPING.md
@@ -196,7 +196,7 @@
 security impact of not making changes, and judgement calls will be made, with
 options to allow providing the old behavior.
 
-## clang-tidy
+### clang-tidy
 
 clang-tidy is a tool that can be used to identify coding style violations, bad
 design patterns, and bug prone constructs. The checks are implemented in the