Update start zone defaults (#279)

Author: Panzerhandschuh

fgd/brush/trigger/zone_timer_start.fgd

@@ -12,8 +12,8 @@
 		]
 	checkpoints_required(boolean) : "Checkpoints Required" : 0 : "Is the player required to activate all checkpoints before progressing? Otherwise, checkpoint zones may be skipped. If there are multiple stages, this only applies to Stage 1."
 	checkpoints_ordered(boolean) : "Checkpoints Ordered" : 1 : "Do the checkpoints in this segment have a logical order, even if the player is not required to activate them all? If there are multiple stages, this only applies to Stage 1."
-	safe_height(float) : "Safe Height" : -1 : "Height that the player must be under to start a run of this stage track. Safe height is not a factor in activating the stage when running the full main track. -1 = full zone, 0 = base of zone, > 0 = custom height."
-	max_velocity(float) : "Max Velocity" : 0 : "Maximum speed that the player can move at. 0 = unlimited, > 0 = custom limit."
+	safe_height(float) : "Safe Height" : 0 : "Height that the player must be under to start a run of this stage track. Safe height is not a factor in activating the stage when running the full main track. -1 = full zone, 0 = base of zone, > 0 = custom height."
+	max_velocity(float) : "Max Velocity" : -1 : "Maximum speed that the player can move at. -1 = gamemode default, 0 = unlimited, > 0 = custom limit."
 	bhop_enabled(boolean) : "Force Enable Bhop" : 0 : "Overrides the game mode's settings to allow bhopping on this track. If disabled, zone_allowbhop can be used to allow bhopping in specified regions."
 	restart_destination(target_destination) : "Restart Destination (Required)" : : "The entity specifying the point to which the player should be teleported when restarting a run."
 	]