Updated Client server discovery lifecycle (markdown)

Client-server-discovery-lifecycle.md

@@ -99,7 +99,27 @@ So, first We create a new interface for the sbt launcher, called `xsbt.ServerMai
 ```java
 package xsbti;
 
+/** The main entry point for a launched service.
+ * 
+ * A class implementing this must:
+ * 
+ * 1. Expose an HTTP port that clients can listen on, returned via the start method.
+ * 2. Accept HTTP HEAD requests against the returned URI. These are used as "ping" messages to ensure
+ *    a server is still alive, when new clients connect.
+ * 3. Create a new thread to execute its service
+ */
 public interface ServerMain {
+  /**
+   * This method should launch a new thread(s) which run the service.  After the service has
+   * been started, it should return the port
+   * 
+   * @param configuration
+   *          The configuration used to launch this service.
+   * @return
+   *    A URI denoting the Port which clients can connect to.  Note:  only HTTP protocol and 
+   *    localhost/127.0.0.1/::1 addresses are supported in the URI. Any other return value will
+   *    cause this service to be shutdown.
+   */
   public java.net.URI start(AppConfiguration configuration);
 }
 ```