docs: update README

README.md

@@ -106,7 +106,7 @@ brew install easydict
 
 如果编译出现签名错误，请在 target 的 `Signing & Capabilities` 页面改用你自己的开发者账号。如果你还不是苹果开发者，只要去 https://developer.apple.com/ 免费注册一下就可以。
 
-构建环境：Xcode 13, macOS Big Sur 11.3。 为避免不必要的问题，建议使用最新的 Xcode 和 macOS 版本 https://github.com/tisfeng/Easydict/issues/79
+构建环境：Xcode 13+, macOS Big Sur 11.3+。 为避免不必要的问题，建议使用最新的 Xcode 和 macOS 版本 https://github.com/tisfeng/Easydict/issues/79
 
 ### 签名问题 ⚠️
 

docs/README_EN.md

@@ -106,7 +106,7 @@ Just download this Repo, then use [Xcode](https://developer.apple.com/xcode/) to
 
 If a signature error occurs during compilation, please use your own developer account on the `Signing & Capabilities` page of the target. If you are not an Apple developer yet, just go to https://developer.apple.com/ and register for free.
 
-Build environment: Xcode 13, macOS Big Sur 11.3. To avoid unnecessary problems, it is recommended to use the latest Xcode and macOS version https://github.com/tisfeng/Easydict/issues/79
+Build environment: Xcode 13+, macOS Big Sur 11.3+. To avoid unnecessary problems, it is recommended to use the latest Xcode and macOS version https://github.com/tisfeng/Easydict/issues/79
 
 ### Signature Problem ⚠️