docs: update to represent change to script

Author: isabelroses

README.md

@@ -55,8 +55,9 @@ To enable rounded borders:
 ```sh
 git clone https://github.com/catppuccin/fcitx5.git
 mkdir -p ~/.local/share/fcitx5/themes/
-./fcitx5/enable-rounded.sh
-cp -r ./fcitx5/src/* ~/.local/share/fcitx5/themes
+cd fcitx5
+./enable-rounded.sh
+cp -r ./src/* ~/.local/share/fcitx5/themes
 ```
 
 To disable rounded borders use `disable-rounded.sh`.