added interdoc xref

docs/modules/tutorials/pages/beginner/hello_input_system.adoc

@@ -374,7 +374,7 @@ inputManager.addMapping("Pause",  new KeyTrigger(usersPauseKey));
 
 [IMPORTANT]
 ====
-Link to user-proposed solutions: xref:beginner/solutions.adoc[Some proposed solutions] +
+Link to user-proposed solutions: <<beginner/solutions.adoc#hello-input,Some proposed solutions>> +
 +++<u>Be sure to try to solve them for yourself first!</u>+++
 ====