Document how to set up Lombok in Eclipse

Provide step by step instructions how to install Lombok in Eclipse.

This will make it easier for developers to get up and running,
rather than spending time figuring it out.

Change-Id: I1d76d085c2a4ee34f455f0e8247ad26bda6dd3a1
diff --git a/README.md b/README.md
index 8ce043c..5392da8 100644
--- a/README.md
+++ b/README.md
@@ -142,3 +142,24 @@
 * ClientId []: <provided client id from previous step>
 * ClientSecret []: <provided client secret from previous step>
 
+### Contributing to the GitHub plugin
+
+The GitHub plugin uses the lombok library, which provides a set of
+annotations to reduce the amount of boilerplate code that has to be
+written.
+
+To build the plugin in Eclipse, the Lombok Eclipse integration must be
+installed.
+
+Download lombok.jar from http://projectlombok.org/ and install:
+
+
+```
+  java -jar lombok.jar
+```
+
+Follow the instructions to select your Eclipse installation if the
+installer cannot detect it automatically.
+
+After the installation, Eclipse must be restarted and compilation
+errors should disappear.