8161965: Create initial javadoc description for modules

Reviewed-by: mchung, alanb, abuckley

jaxws/src/java.activation/share/classes/module-info.java

@@ -23,6 +23,9 @@
  * questions.
  */
 
+/**
+ * Defines the JavaBeans Activation Framework (JAF) API.
+ */
 module java.activation {
     requires public java.datatransfer;
     // dependence on java.beans.Beans to be eliminated