When you add headings to your document ... Integrating tabs with your Google Docs outline While creating an outline is useful ...

You must use Google Docs built-in header styles for this to work. To add a heading in Google Docs, highlight the text you want to turn into a heading, select Format > Paragraph Styles, and select ...

header, and footer, show line number after every N line, etc., can also be set by you. When the options are set, press the Apply button. It will immediately add line numbers to your Google Docs ...