To add an attached PDF by link. D1 Middle Term Report
You cannot create an empty folder and then add files to that folder, but instead, the creation of a folder must happen together with the addition of at least a single file. On Github you can do it this way:
go to the folder within which you would like to make another folder
Click on New file
on the text field for the file name, first, write the folder name you want to create
then type /. This creates a folder
you can add more folders similarly
finally, give the new file a name, (eg. .gitkeep which is conventionally used to allow git to track otherwise empty folders; not a git feature though)
finally, click Commit new file.