This function uploads a specific file to a specific folder.
upload_folder_file(canvas, folder_id, file_name, generate_message = TRUE)If generate_message is TRUE, a confirmation message indicating
that the file has been successfully uploaded.
An object containing the Canvas API key and base URL,
obtained through the canvas_authenticate function.
The ID of the folder to which the file is uploaded.
The path to the local file that should be uploaded.
A logical expressing whether a message should
be shown after a succesful upload; defaults to TRUE.
Note that the user should have rights to access the folder.
get_course_root_folder() and get_user_folders()