Image width argument

This argument is meant to be analogous to the Image height argument but for images.

Usage of this argument is generally discouraged, as we always set the default image height by default, so that also passing a width is either unnecessary or may lead to changes in the image's correct aspect ratio.

\Image[Tank_man_standing_in_front_of_some_tanks.jpg]
{width=150}

\Image[Tank_man_standing_in_front_of_some_tanks.jpg]
{width=550}