TongDa Railway

Update route generate function. Now railway only generate in some random area.

* Rough steps for generating the route map:
 * 1. Use a low-discrepancy sequence to randomly and uniformly select stations within the area
 * 2. Remove invalid points (e.g., points located in the ocean)
 * 3. Connect the stations to form a Delaunay triangulation network
 * 4. Remove edges such that adjacent edges along the circumference are above a specified angle
 * 5. Remove edges to ensure the maximum degree of a node is 4. Assign stations corresponding to exits based on node degree
 * 6. Return the nodes and all nodes connected to each
 * 7. Use Hungarian matching to match an edge to each station exit
 * 8. Generate connections based on the matching results