Update README.md

Author: sunnyyoung

README.md

@@ -31,7 +31,7 @@ $ brew install sunnyyoung/repo/wechattweak-cli
 
 1. Download the [WeChatTweak-CLI](https://github.com/Sunnyyoung/WeChatTweak-CLI/releases/latest/download/wechattweak-cli)
 2. Remove file attributes: `xattr -d com.apple.quarantine wechattweak-cli`
-3. Make sure the binary executable: `chmod + x wechattweak-cli`
+3. Make sure the binary executable: `chmod +x wechattweak-cli`
 4. Run: `wechattweak-cli --install`
 
 ## Usage