toc: remove docs home from left navigation (#21528)

Author: lilin90

TOC.md

@@ -1,7 +1,6 @@
 <!-- markdownlint-disable MD007 -->
 <!-- markdownlint-disable MD041 -->
 
-- [Docs Home](https://docs.pingcap.com/)
 - About TiDB Self-Managed
   - [What is TiDB Self-Managed](/overview.md)
   - [TiDB 8.5 Release Notes](/releases/release-8.5.0.md)