Added some walls at the side of pink station.

Update Changelog
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Added a wall near the the end of both green and blue railway to avoid skipping to pink station.
Added a checkpoint at the middle of blue railway.
Rearranged some railways to reduce bendy/squished railways.
Removed some signs that are not fair to avoid.
Reduced the width of the dweller make it more like a wall than a block.
Added a checkpoint warning in the arrow seal dialogue.
Added Sync Points to Sync up the trains
Added Arrow on signs at the pink railways

Changed Icon

Initial Release!