Update README.md

fixes vaadin#79

README.md

@@ -1,2 +1,10 @@
-The documentation for the **GWT Maven Plugin** is here: http://mojo.codehaus.org/gwt-maven-plugin/
+# Vaadin Maven Plug-in
 
+To print information about this plugin's goals and their parameters you can use maven-help-plugin's [describe goal](https://maven.apache.org/plugins/maven-help-plugin/describe-mojo.html):  
+`mvn help:describe -DgroupId=com.vaadin -DartifactId=vaadin-maven-plugin -Ddetail`
+
+---
+
+The documentation for the GWT Maven Plugin, on which this plugin is based, can be found [here](https://gwt-maven-plugin.github.io/gwt-maven-plugin/index.html).
+
+Information about the goals that the GWT Maven Plugin provides can be found [here](https://gwt-maven-plugin.github.io/gwt-maven-plugin/plugin-info.html).