README: "Apache OpenWhisk" at top; add building from source instructions (#187)

diff --git a/README.md b/README.md
index e500eeb..0855830 100644
--- a/README.md
+++ b/README.md
@@ -17,7 +17,7 @@
 #
 -->
 
-# Using the Alarm package
+# Apache OpenWhisk Alarm Package
 
 [![License](https://img.shields.io/badge/license-Apache--2.0-blue.svg)](http://www.apache.org/licenses/LICENSE-2.0)
 [![Build Status](https://travis-ci.org/apache/incubator-openwhisk-package-alarms.svg?branch=master)](https://travis-ci.org/apache/incubator-openwhisk-package-alarms)
@@ -127,6 +127,10 @@
 
  **Note**: The parameter `maxTriggers` is deprecated and will be removed soon.  To stop the Trigger, use the `stopDate` parameter.
 
+# Building from Source
+
+To build this package from source, execute the command `./gradlew distDocker`
+
 # Disclaimer
 
 Apache OpenWhisk Package Alarms is an effort undergoing incubation at The Apache Software Foundation (ASF), sponsored by the Apache Incubator. Incubation is required of all newly accepted projects until a further review indicates that the infrastructure, communications, and decision making process have stabilized in a manner consistent with other successful ASF projects. While incubation status is not necessarily a reflection of the completeness or stability of the code, it does indicate that the project has yet to be fully endorsed by the ASF.