Minor : update bat tool for symlink (deprecated folder)

_ExternalSymLink.bat

 mklink /J "%cd%\Assets\UnityShaderEditor" "%cd%\External\MaterialGraphProject\Assets\UnityShaderEditor"
 mklink /J "%cd%\Assets\NewUI" "%cd%\External\MaterialGraphProject\Assets\NewUI"
 mklink /J "%cd%\Assets\GraphFramework" "%cd%\External\MaterialGraphProject\Assets\GraphFramework"
-mklink /J "%cd%\Assets\MaterialGraphInterface" "%cd%\External\MaterialGraphProject\Assets\MaterialGraphInterface"
 pause