I wasn’t thinking about Google Sites at all. Not now and not earlier.
I’m trying to picture or imagine what a “template” is. It’s not clear to me. Very often, people use pictures or drawings or diagrams to illustrate concepts. As the saying goes, a picture is worth a thousand words. I’m not criticizing the documentation, but I think I would understand the concepts better if there were some pictorial illustrations. As an engineer, we use schematics, block diagrams, drawings, etc. As a coder, I like flowcharts.