I am outputting ActivityPub/ActivityStreams content for the listing of what is in a directory.
Think of it as the AP/AS version of output from the `ls` command.
AP/AS has a whole bunch of stuff that can be used to represents files. Even sub-types of files
https://www.w3.org/TR/activitystreams-vocabulary/#object-types
And, while AP/AS has 'Collection' (and 'CollectionPage') —
https://www.w3.org/TR/activitystreams-vocabulary/#dfn-collection
AP/AS doesn't have a 'Directory' type (as a sub-type of 'Collection')
