All nodes within the desk structure has an ID assigned to it. Normally, the ID is assigned automatically based on the title of the item, but some items require a manually assigned ID.
One example of this is the document list item - its ID refers to a specific document ID, and as such it needs to be manually assigned.
Setting an ID can be done by calling the id() method:
S.documentListItem()
.id('website-featured-articles')
.schemaType('article-set')
.title('Site config')