Copies a page
Creates a copy of a page together with its subpages. template_id is the ID of the source page. title is optional and defaults to Copy of <source title>. When copying a doc, pass project_id to place the copy in a project; a subpage copy stays next to the source and takes no project_id. Template docs cannot be copied this way — use apply_template_as_docOPERATION
.