I suggest implementing the ability to set bookmarks in PDF files. There is a "Headings" system in documents that automatically generates a table of contents. It would be convenient if, when saving files in docx, doc, rtf and similar PDF format, the "Headers" were converted into bookmarks.

https://helpx.adobe.com/acrobat/using/page-thumbnails-bookmarks-pdfs.html

https://erinwrightwriting.com/create-bookmarks-in-pdfs-with-adobe-acrobat/