Transportation fixes and more secrets

 - Fixed transporters having the potential to zoom in before they're used.
- Modified crane carrier clearance to fix visual issues looking like the player is half in the ground.
- Modified "Secondhand" map to have a spike pit rather than a drop to the room below.
- Added secret to "Secondhand" map.
- Added secret to "Gates Below" map.
- Modified a rising platform spike jump to be easier in "Peaks and Valleys" map.
- Fixed visual issue in "Peaks and Valleys" after rising platform spike jump.
- Modified "Peaks and Valleys" map to have a hint when riding up.
- Added brief invulnerability when entering doors.