How to use it ?
1- Create a new spreadsheet on Google drive
2- In the spreadsheet menu go to Extensions -> Apps Script
3- Create 3 srcipt files : initSidebar, generateArborescence, checkFolderExists
4- Create 1 HTML file : sidebar
5- Copy / paste the code from this repository to the corresponding files created
6- Check Arborescence sidebar tutorial PDF for more informations on how to use it