Explain that you cannot create content pages under taxonomy directories

[jmooring]

If you have a taxonomy named "tags" you must not do this:

hugo new content/tags/foo.md

The only files you should create under a taxonomy directory are section pages to contain taxonomy or term metadata. For example:

content/tags/
├── foo/
│   └── _index.md
└── _index.md

Not quite sure where to put this in the docs.

Reference: gohugoio/hugo#7975

[davidsneighbour]

Can you add that hugo new content/tags/foo is allowed if there is an archetype foo/_index.md with frontmatter? I am pretty sure that I have that somewhere in use, but can't find it right now.

[jmooring]

This will be addressed in #2307