message: doc: add error resource document
diff: @@ -101,7 +101,17 @@ GET /health
  ```javascript
  GET /error
  -
  +[
  + {
  + "method": "error",
  + "date": 1346846400,
  + "errType": "myError",
  + "message": "",
  + "stack": "",
  + "traceId": "1231455",
  + "path": "/xxx/xx.log"
  + }
  +]
  ```
  