A way to display max_speed in non-locomotive rolling stock tooltips

[curiosity]

I am certain that a suggestion to blanket do this for all rolling stock will be declined "not to confuse casual vanilla players" or something, therefore this request.

Add a property to the rolling stock prototype that would determine whether to show the maximum speed in the tooltip. Call it display_max_speed or show_max_speed or, to be consistent with the resistance display, hide_max_speed.

This is useful because you may have a wagon with a lower max speed than a locomotive, and not seeing that it is actually the wagon that limits the speed confuses players.

[LuziferSenpai]

+1

[lovely_santa]

+1 for obvious reasons