bug(docs): fix title of thuai8 ai_manual

Author: Timothy-Liuxf

docs/contests/THUAI8/intro/ai_manual.md

@@ -1,7 +1,7 @@
 ---
 title: THUAI8 西游真经劫 AI 编写手册
 sidebar_label: AI 编写手册
-------
+---
 
 ## 目录