SLING-7167 Adjust READMEs

add uniform header linking to Sling project

git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1810936 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/fling/README.md b/fling/README.md
index d5eff0f..06af2ca 100644
--- a/fling/README.md
+++ b/fling/README.md
@@ -1,5 +1,6 @@
-Sling Fling Sample
-==================
+# Apache Sling Fling Sample
+
+This module is part of the [Apache Sling](https://sling.apache.org) project.
 
 This is a sample using _Sling Models_, _Sling Query_, _Sling Scripting Thymeleaf_, _Sling Validation_, _Sling Commons Messaging_ (latest snapshot) and _Sling Commons Messaging Mail_ (latest snapshot).