Is it the intention that all templates and modules with documentation are in the Category:Template documentation? I think not, and I tried to fix it, but I guess me not being a translation admin is a hurdle.
Topic on Template talk:Documentation/Flow
As I wrote in edit summary, for example, Template:Caution is not only a template but its documentation. So it is correct behavior.
Ah, I was wondering what Template:Caution had to do with anything, but now I see you mentioned it as example. Thanks for the clarification.