SLING-7167 Adjust READMEs

add uniform header linking to Sling project

git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1810820 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/README.md b/README.md
index 542068f..e2df165 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,7 @@
 # Apache Sling RRD4J metrics reporter
 
+This module is part of the [Apache Sling](https://sling.apache.org) project.
+
 This is a bundle that stores metrics on the local filesystem using
 [RRD4J](https://github.com/rrd4j/rrd4j).
 
@@ -13,4 +15,4 @@
 Go to the Apache Felix Web Console and configure 'Apache Sling Metrics reporter
 writing to RRD4J'. The reporter will start storing metrics once data sources
 have been added and the configuration is saved. Please note, the metrics file
-is recreated/cleared whenever the configuration is changed.
\ No newline at end of file
+is recreated/cleared whenever the configuration is changed.