GET requests to empty folders - clarify

[michielbdejong]

"GET requests to empty folders" maybe already refer ahead to the fact that unless there is a document by the same name, folders are never a 404.

[michielbdejong]

and later, "In contexts outside of this document, non-empty folders may be
called 'existent', while empty folders may be called 'non-existent'." - but be aware that even if you call it a non-existent folder, a URL that ends in a slash will never give a 404.