Warn about snapshots

git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1789329 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/fling/README.md b/fling/README.md
index f90bd00..4fdebc1 100644
--- a/fling/README.md
+++ b/fling/README.md
@@ -3,6 +3,8 @@
 
 This is a sample using _Sling Models_, _Sling Query_, _Sling Scripting Thymeleaf_, _Sling Validation_ (latest snapshot), _Sling Commons Messaging_ (latest snapshot) and _Sling Commons Messaging Mail_ (latest snapshot).
 
+As it is using some snapshots it might be unstable from time to time, feel free to ask on our mailing list if unsure!
+
 * [Sling Models](http://sling.apache.org/documentation/bundles/models.html)
 * [Sling Query](https://github.com/Cognifide/Sling-Query)
 * [Sling Scripting Thymeleaf](http://sling.apache.org/documentation/bundles/scripting/scripting-thymeleaf.html) ([Thymeleaf](http://www.thymeleaf.org/), [Sling i18n](http://sling.apache.org/documentation/bundles/internationalization-support-i18n.html))