Update url of Getting Started Guide.

src/main/javadoc/overview.html

@@ -2,5 +2,5 @@
 <p>This package includes the resources needed to write custom Hooks for MQTT.Cool.<br>
 MQTT.Cool requires a Hook to be plugged onto it to handle authentication and authorization requests.<br>
 Please refer to the provided 
-<a href="https://mqtt.cool/docs/server/guides/MQTT.Cool+Getting+Started+Guide.html" target="_blank">MQTT.Cool Getting Started Guide</a> for further details about the role of the Hook in MQTT.Cool and how to configure it.</p>
+<a href="https://docs.mqtt.cool/server/guides/MQTT.Cool+Getting+Started+Guide.html" target="_blank">MQTT.Cool Getting Started Guide</a> for further details about the role of the Hook in MQTT.Cool and how to configure it.</p>
 </body>