This is as simple as dragging the html5game folder, scripts folder, and index.html file (that is created when you compile your project) onto your site
This is incorrect - you don't have to upload the scripts folder. The scripts folder is just a folder containing the script resources. You can check it out, it contains GML files with the GML-versions of scripts in them. In fact, by uploading the scripts folder you are putting a part of your source code online, without any obsfucation. Bad stuff.
You only need to upload the index.html and the html5game folder (by the way, it's not necessarily called 'html5game', you can change that in the Global Game Settings). Optionally you can also upload the favicon.ico file, but I would only recommend doing that if you use your own icon, otherwise you'll get a GM:Studio logo.
So, please edit that part in your tutorial