feat: update README

README.md

 # yunheBot
 
 ## 问答接口
-
-url:    /api/v1/completion
-methon: POST
-request:
+    url:    /api/v1/completion
+    methon: POST
+    request:
         ```json
         {
             "prompt": "your question here", // 提问
@@ -13,7 +12,7 @@ request:
             "stream": false                 // 是否流式返回，预留
         }
         ```
-Response:
+    Response:
         ```json
         {
             "code": 200,                         // 状态码，200为请求成功，其余为失败