G Suite team wrote
in a blog post as "We're adding a quick-access side panel to the Docs editors and Google Calendar to help you quickly access other G Suite products without leaving what you're working on"
This latest side bar will help users to access three G Suite products from Docs itself - Sheets, Slides, and Drawings. G Suite also gives users the liberty to minimise the side panel.
Further the post read "We hope that this integration will help you work more efficiently within and across G Suite"
