Include lightbox effect (make it bigger on click) for images

[juanmaguitar]

From WordPress 6.4 images can enable lightbox functionality to let visitors enjoy full-screen, interactive images on click.

This would be extremely helpful for documentation purposes, especially for diagrams used in Handbooks.

cc: @ndiego @adamwoodnz

[ndiego]

This is a great idea. It's implemented on the new 6.4 release landing page, so it seems possible once we are using blocks with the redesign.