Update mysql-index.md

Snailclimb · Snailclimb · commit 503662520777 · 2022-04-07T13:55:55.000+08:00
diff --git a/docs/database/mysql/mysql-index.md b/docs/database/mysql/mysql-index.md
@@ -5,7 +5,7 @@ tag:
   - MySQL
 ---
 
-
+> 感谢**[WT-AHA](https://github.com/WT-AHA)** 对本人的完善，相关 PR：https://github.com/Snailclimb/JavaGuide/pull/1648 。
 
 ## 何为索引？有什么作用？
 
