Add the option for assessing the editor mode

There is no option for accessing the editor mod for the app that can assess when learning a program
I am currently doing the responsive web design in there when there is a example code but we can't see the output of the example code that is given
It will much more convenient that if there will be a button to access the editor mode to see the output of the example code

Request to kindly look in to it

Start by locating the responsive web design lesson screen and the existing handling of example code in the Flutter app. Clarify how an editor mode should be opened and what output it must display; the work is done when the requested option is defined, implemented, and verified for the reported lessons.

Written by the indexing model from the issue text.