fix: update README checkout example to release/1.14.x (#772)

Author: RiskeyL

README.md

@@ -116,7 +116,7 @@ Our published documentation site only hosts the latest version of Dify. To view
 ```bash
 git clone https://github.com/langgenius/dify-docs.git
 cd dify-docs
-git checkout release/1.14   # replace with the version you want
+git checkout release/1.14.x   # replace with the version you want
 npm i -g mintlify
 mintlify dev
 ```