Background
The main menu checkbox impacts Vector's layout, when there's no ToC and the main menu is open, it is 2 column, and when its closed its single column. Because the checkbox is a child of the grid container, we cannot directly update the grid template columns based off the checkbox. Moving the checkbox simplifies our grid styles and help prepare the layout for the full width toggle
AC
- no visual changes
- the main menu checkbox is outside of .mw-page-container-inner
Developer notes
This task will involve cached HTML changes
This task is ideally done after T318011, which needs to be replaced/moved when the main menu checkbox is moved