In zsh, SF CLI retrieving classic email template in Unfiled Public folder

 This seems to be a zsh-only issue, for Salesforce devs who now have followed Apple's recommendation to use zsh as the default shell.  The successful command to retrieve a template needs to be like this:

 sfdx project retrieve start -m EmailTemplate:"unfiled\$public/Employee_Created" -o myDevOrg

The key here is to escape the dollar sign, but not the slash.