Doc: add a simple diagram to the 2-up & booklet pages

[Lucas-C]

It would be useful to add a simple diagram to these pages, visually explaining what the commands do:

• 2-up command documentation page
• booklet command documentation page

draw.io or any other software could be used to produce the diagrams.

Maybe some other commands documentation pages could also benefit from a diagram to visually explain what they do.

[d-mahi14]

Hello @Lucas-C , Mahi here I would like to work on this issue...could you please assign it to me?

[Lucas-C]

Sure, I've just assigned you @d-mahi14 👍 🙂