You can create & add a document outline in Google Docs using this guide. Difference between Table of contents & Document Outline explained.

Without adding headings, you can't create an outline or table of contents in Google Docs. Headings let you easily jump through different sections or move straight to the summary in long documents.

Google upgraded Docs for the web and Android today with the announcement of automatic outlines.

Adding a summary to a Google Docs document is useful for both the author and the reader. For the reader, it gives them a brief overview of the document without having to read the whole thing. It ...