Writing docs.

@@ -20,7 +20,7 @@ public enum SystemCommandEnumType {
           QUERY(":q         ","【:q 关键字】查询聊天记录"),
              AI(":ai        ","开启 AI 模式"),
             QAI(":qai       ","关闭 AI 模式"),
-            PREFIX(":pu     ","模糊匹配用户")
+         PREFIX(":pu        ","模糊匹配用户")
 
     ;