chore: adjust heading level

Author: brc-dd

CHANGELOG.md

@@ -1,6 +1,6 @@
-# [2.0.0-alpha.1](https://github.com/vuejs/vitepress/compare/v1.6.2...v2.0.0-alpha.1) (2025-01-22)
+## [2.0.0-alpha.1](https://github.com/vuejs/vitepress/compare/v1.6.2...v2.0.0-alpha.1) (2025-01-22)
 
-## Features
+### Features
 
 - upgrade vite to v6 ([#4504](https://github.com/vuejs/vitepress/issues/4504)) ([6a2efc3](https://github.com/vuejs/vitepress/commit/6a2efc385c90b088241db05f5263b2f3e1f757cf))