docs: add en-US changelog

docs/markdown/changelog-v3.en-US.md

@@ -0,0 +1,29 @@
+# Changelog
+
+### Tips
+
+The current document is the changelog of Vant 3.x. If you want to view the changelog of Vant 2.x, please visit [Vant 2.x Changelog](https://youzan.github.io/vant/#/en-US/changelog).
+
+### Intro
+
+Vant follows [Semantic Versioning 2.0.0](https://semver.org/lang/zh-CN/).
+
+**Release Schedule**
+
+- Patch version：released weekly, including features and bug fixes.
+- Minor version：released every one to two months, including backwards compatible features.
+- Major version：including breaking changes and new features.
+
+## Details
+
+### [v3.0.0-beta.6](https://github.com/youzan/vant/compare/v2.10.12...v3.0.0-beta.6)
+
+`2020-11-01`
+
+**Bug Fixes**
+
+- Calendar: watch maxData/minDate and reset [#7412](https://github.com/youzan/vant/issues/7412)
+- Swipe: incorrect lazy render when loop is false [#7465](https://github.com/youzan/vant/issues/7465)
+- Swipe: item should only rendered once [#7466](https://github.com/youzan/vant/issues/7466)
+- Tabs: skip initial animation [49e877](https://github.com/youzan/vant/commit/49e87756c70b33e1a56620ebee3c0aa53fb9fc86)
+- ActionBar: fix typing [#7440](https://github.com/youzan/vant/issues/7440) [#7442](https://github.com/youzan/vant/issues/7442)

docs/markdown/changelog-v3.zh-CN.md

@@ -2,7 +2,7 @@
 
 ### 提示
 
-当前文档为 Vant 3.x 版本的更新日志，如需查询 Vant 2.0 的更新内容，请访问 [Vant 2.0 更新日志](https://youzan.github.io/vant/#/zh-CN/changelog)。
+当前文档为 Vant 3.x 版本的更新日志，如需查询 Vant 2.x 的更新内容，请访问 [Vant 2.x 更新日志](https://youzan.github.io/vant/#/zh-CN/changelog)。
 
 ### 介绍
 
@@ -14,6 +14,8 @@ Vant 遵循 [Semver](https://semver.org/lang/zh-CN/) 语义化版本规范。
 - 次版本号：每隔一至二个月发布，包含新特性和较大的功能更新，向下兼容。
 - 主版本号：发布时间不定，包含不兼容更新。
 
+## 更新内容
+
 ### [v3.0.0-beta.6](https://github.com/youzan/vant/compare/v2.10.12...v3.0.0-beta.6)
 
 `2020-11-01`

vant.config.js

@@ -425,7 +425,7 @@ module.exports = {
                 title: 'Advanced Usage',
               },
               {
-                path: 'changelog',
+                path: 'changelog-v3',
                 title: 'Changelog',
               },
               {