Mobile markup: add width for the code

[vitaly-zdanevich]

Now we have this:

Near line numbers we have unused space, also margin of the code block eats valuable pixels.

[go101]

@vitaly-zdanevich
What is you phone device?
On my Android phone, the code blocks can be dragged to view the initially invisible parts.
Can them be dragged on your phone?

And in the landscape mode, the width is large enough to show every lines.

[vitaly-zdanevich]

My phone is Poco X3 Pro.

Yes I can drag, but you can optimize the layout for small width.

[go101]

Could you elaborate more on how to optimize it?
A PR is preferred if possible.

[vitaly-zdanevich]

Ok, I will do a pull request.