There's a new admin dashboard in all Matrix Themes installed from February 2021.
The new admin section is being added by js file, so you won't find the documentation, shortcodes and other links in HTML.
As I wrote before, all themes installed from 01-02-2021 by default include the new admin menu, so you don't need to do anything.
If you're using a Matrix Theme installed before February 2021, you can update your website on your own following the below step-by-step tutorial:
Note: The new admin dashboard will be opened by default in Matrix themes menu. To switch back from any other section, please click the header title Matrix
If you don't want the new dashboard appear by default in menu, please use the version 1.8.6. Here the dashboard menu is displayed only when you click the header title Matrix