Adds invision script to prompt before reloading

config/dotjs/projects.invisionapp.com.js

@@ -0,0 +1,7 @@
+window.addEventListener( "beforeunload", (event)=>{
+	  // Cancel the event as stated by the standard.
+	event.preventDefault();
+	// Chrome requires returnValue to be set.
+	event.returnValue = 'This is invision, not the site. Are you sure?';
+	return 'This is invision, not the site. Are you sure?';
+} );