Set help message, how to run only one UI test spec file

plugins/TestRunner/Commands/TestsRunUI.php

@@ -22,6 +22,10 @@ class TestsRunUI extends ConsoleCommand
     {
         $this->setName('tests:run-ui');
         $this->setDescription('Run screenshot tests');
+        $this->setHelp("Example Commands
+        \nRun one spec:
+        \n./console tests:run-ui UIIntegrationTest
+        ");
         $this->addArgument('specs', InputArgument::OPTIONAL | InputArgument::IS_ARRAY, 'Run only a specific test spec. Separate multiple specs by comma, for instance core,integration', array());
         $this->addOption("persist-fixture-data", null, InputOption::VALUE_NONE, "Persist test data in a database and do not execute tear down.");
         $this->addOption('keep-symlinks', null, InputOption::VALUE_NONE, "Keep recursive directory symlinks so test pages can be viewed in a browser.");