SLING-7167 Adjust READMEs

add uniform header linking to Sling project

git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1810831 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/README.md b/README.md
index b3b43ac..843c199 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,5 @@
-Apache Sling Threads
+# Apache Sling Thread Support
+
+This module is part of the [Apache Sling](https://sling.apache.org) project.
 
 Support for thread handling like pooling.