G-Suite - formerly known as Google Apps - posted a notice about an update to Google Docs earlier this week.
While users have always been able to add a Table of Contents (TOC) to a document, you can now add a TOC with page numbers. (as I have done within this document) The entries are still clickable, but do not appear as blue underlined links anymore. This is intended to make the TOC more readable - and in my opinion it does - while still providing the ability to “jump” to a section of the document for ease of use.
Note: The TOC feature reads the Text Style used in the document, so it requires that users select a line of text and apply different Headings in the Text Style drop down menu: