TODO
Folder to create the new document in.
Only consulted when a document is actually created; replacing the content of a document that already exists leaves that document where it is.
When this [[NewContent]] came from a [[Relate.DocumentLinkField]], omitting the folder does not mean "the library root" — it means that field's own default folder, which is the library root only while the field is left unconfigured; a field given a default folder or a dated subfolder type files into that subfolder instead. Since [[Folder.documentsAsMap]] is not recursive, a script that looks a filename up in the library root and then writes without an explicit folder can fail to find its own file next run, and upload a fresh copy every time. Pass the folder you searched.
TODO
Example