docs: Updating documentation and license boilerplates in all files

Change-Id: I321fb0d85aaddf9150ed496fe03ee0e4dc738761
diff --git a/AUTHORS.md b/AUTHORS.md
index 36f85b6..c06fd27 100644
--- a/AUTHORS.md
+++ b/AUTHORS.md
@@ -1,5 +1,5 @@
 ndn-cxx authors
-===================
+===============
 
 ## The primary authors are (and/or have been):