drjyounger selectiveCodeConcatenate .cursorrules file for Python

The intent of this program is to allow the user to select which files and folders get included in the final concatenation. 

Upon running the program, instead of concatentating the entire contents of the specified folder,  it should open an Explorer/Finder UI interface with checkboxes beside files and folders which allow the user to choose which files and folders get included in the final concatenation.  

Then there is button that says "Go" and this activates the concatenation funcation.  Using the same logic and formatting as the @main.py program for the final concatenated file.  If a folder is checked off, then all recursive files and folders shold be included.