Tiny Rock final

* Fixed carts getting progressively louder every round
* Reworked player detection zone to (hopefully) fix rounds occasionally not ending when one team is fully eliminated

* Widened the thinner parts of the cart tracks
* Fixed doors not opening during feedback round
* Re-added the mid-round spawn

* Temporarily reverted to old map logic due to players getting stuck inside payload carts very easily
* Re-added some clipping I accidentally deleted in a6

* Map no longer instantly crashes the server (oops)

* This map now uses Leezo's Arena PLR game logic
* Completely rebuilt cart track paths
* Moved spawns to a new location to account for new track paths
* Removed the 2fort bridge. Long live the 2fort bridge.
* Blocked off old, now-redundant areas

Map prefix is now "arena_" rather than "aplr_". Thanks to @leezo for creating the new gamemode logic!

* Changed time of day (rotated environment lighting so each side is more evenly-lit)
* Did a bit of detailing cos why not
* Moved capture zones back into the mines
* Made mines slightly more spacious to account for new cap zone position
* Added a new route for non-jumpy classes (e.g. Heavy) to reach the bridge roof in the middle
* -50% 2fort bridge (removed wood fences on the bridge to make it easier to access)
* Made doorways through the lower bridge larger
* Added some friends

* Added another spawn door
* Added a temporary resupply locker to spawns
* Walled up the cap zone huts to kill some insane sightlines
* Fixed a couple misplaced light sources
* (Just for testing) Added notes for imp hosts
* (Just for testing) Added a backdrop to said notes to make them a bit easier to read