The link you provided is for building/using Workspace Templates within Monday Apps you’ve created. So to find the Feature section you need to first navigate to your application.
If you are NOT currently building a Monday App, this is the article https://support.monday.com/hc/en-us/articles/360010785460-What-are-Workspaces-?abcb=30311. I don’t see them mention templates like in the other one, so that might only be available when creating Monday apps. But its probably a feature in the works since you can template just about everything else.