You do not need to move the sshd_config file into the chrooted environment. The user does not need access to this file or any other binaries or config files.
Because this only allows for SFTP, they do not need access to such things.
The user will see the dir structure as something like this(will vary depending on what you let them do with it)
Thats it. They don't need anything else.
Also the original problem here is that the tutorial doesnt use the 'stock' install version of openssh. It installs into the /opt directory and therefore all paths would now be relative to that.
If you notice anything blatantly wrong please let me know as I am not an expert, its just that there wasn't enough information about how to do this easily so I copied my working procedure (and tested it).