Updated Flow testing (markdown)

Flow-testing.md

@@ -130,3 +130,26 @@ This flow testing feature should be turned on/off. Add a flag in settings.js. Th
 # CLI
 This flow testing needs to be run on the CLI for targeting to run automatically on Travis CI when receiving a pull request on GitHub.
 When running a command like `grunt test-flow`, Node-RED runs flow testing then outputs each result such as the existing Mocha tests.
+- Run flow test.
+```
+grunt test-flow --testItem="./item.json"
+```
+
+- Command line argument.
+  - --testItem : Specify the json file for which the test target "test-in node ID" and "Label" are set.
+
+  - Example: item.json
+```
+[
+    {
+        "id": "a9890736.34f478", // Test in node ID.
+        "labels": [                   // Label specified for test in node.
+                     "Test Case 01", 
+                     "Test Case 02"
+        ]
+        
+    }
+]
+```
+- Target:
+  - Flow to be tested is `flow<hostname>.json` in user directory.