What is a slug in Adobe InDesign and how can it be used?A slug is an area in Adobe InDesign that allows you to add additional information about a document. It is typically used to store information such as the document title, author name, page number, and other information related to the document. Slugs can be used to help organize documents and make them easier to find. They can also be used to add additional information to a document, such as a copyright notice or contact information.