tweaked f_nametags
- made font 0.01 larger and decreased opacity to make names more visible
- color and size made global variable and move to top (user definable)
- changed key from being forced to 'T' to being the key 'TeamSwitch' is bound to by default
- key that toggles name tags made global variable and moved to top (user definable)
- script displays hint on which key to toggle 5 seconds into the mission