feat: update version to 5.1.7 and add custom userAgent documentation

CHANGELOG_CN.md

@@ -6,6 +6,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 
 ## [Unreleased]
 
+## [5.2.4] - 2025-08-01
+
 - 为所有包添加 `ESM` 版本如 `artplayer/dist/artplayer.esm.js`
 - 识别 `globalThis.CUSTOM_USER_AGENT` 全局变量，用于自定义 `navigator.userAgent`
 - 修复 `artplayer-plugin-danmuku` 初始化时 `mount` 参数缺失的错误