Update notes for v0.50

[p]Truck City v0.50 has just been released. This is the change log:[/p]

• [p]Improvement: truck window cargo selection list width increased[/p]

• [p]Improvement: lateral bar menu for factories and warehouses reordered so parking spot is the last item in the rotation[/p]
• [p]Improvement: increased visibility of Alt mode icons[/p]
• [p]Improvement: added sound effects to the typewritter effect in the tutorials[/p]
• [p]Improvement: lateral bar popup menus repositioned so they are more visible[/p]
• [p]Feature: added new Alt mode icons[/p]
• [p]Bugfix: save menu now correctly shows information on files[/p]