docs: update test script.

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

tests/README.md

@@ -32,3 +32,16 @@ run the following command.
 ```sh
 bat POST localhost:8088/api/push < tests/test.json
 ```
+
+Here is a sample shell code to calculate factorial using while loop:
+
+```sh
+#!/bin/bash
+counter=$1
+while [ $counter -gt 0 ]
+do
+  bat POST https://gorush.netlify.app/api/push < tests/test.json
+  counter=$(( $counter - 1 ))
+  echo $counter
+done
+```

tests/test.json

@@ -3,12 +3,20 @@
     {
       "tokens": ["token_a", "token_b"],
       "platform": 1,
-      "message": "Hello World iOS!"
+      "message": "Hello World iOS!",
+      "title": "Gorush with iOS"
     },
     {
       "tokens": ["token_a", "token_b"],
       "platform": 2,
-      "message": "Hello World Android!"
+      "message": "Hello World Android!",
+      "title": "Gorush with Android"
+    },
+    {
+      "tokens": ["token_a", "token_b"],
+      "platform": 3,
+      "message": "Hello World Huawei!",
+      "title": "Gorush with HMS"
     }
   ]
 }