Update README.md

Author: Soulter

README.md

@@ -5,6 +5,17 @@
 
 One-stop & lightweight solution for metric collecting and analytics.
 
+- One RESTful API collect all your projects' datas!
+  ```json
+  {
+    "metrics_data": {
+        "usage_cnt": 1,
+        "os": "linux",
+        "...", "..."
+    }
+  }
+  ```
+
 ![image](https://github.com/user-attachments/assets/2d8e6267-a3ad-40cb-9957-3310687a5f27)
 
 ## Development