docs(changelog): 2.10.0-beta.3

docs/markdown/changelog.en-US.md

@@ -10,6 +10,14 @@ Vant follows [Semantic Versioning 2.0.0](https://semver.org/lang/zh-CN/).
 - Minor version：released every one to two months, including backwards compatible features.
 - Major version：including breaking changes and new features.
 
+### [v2.10.0-beta.3](https://github.com/youzan/vant/compare/v2.10.0-beta.2...v2.10.0-beta.3)
+
+`2020-08-04`
+
+**style**
+
+- Dialog: fix round-button theme [#6934](https://github.com/youzan/vant/issues/6934)
+
 ### [v2.10.0-beta.2](https://github.com/youzan/vant/compare/v2.10.0-beta.1...v2.10.0-beta.2)
 
 `2020-08-03`

docs/markdown/changelog.zh-CN.md

@@ -10,6 +10,14 @@ 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，预计下一个主版本会与 Vue 3.0 同期发布。
 
+### [v2.10.0-beta.3](https://github.com/youzan/vant/compare/v2.10.0-beta.2...v2.10.0-beta.3)
+
+`2020-08-04`
+
+**style**
+
+- Dialog: 修复 round-theme 弹窗样式错误的问题 [#6934](https://github.com/youzan/vant/issues/6934)
+
 ### [v2.10.0-beta.2](https://github.com/youzan/vant/compare/v2.10.0-beta.1...v2.10.0-beta.2)
 
 `2020-08-03`