Small environment

🎛️Configuration: x_dim = 25, y_dim = 25, max_num_cities = 4, max_rails_between_cities = 2, max_rails_in_city = 3, malfunction_rate=1. / 10000, min_duration=15, max_duration=50

📃 Source: https://gitlab.aicrowd.com/flatland/neurips2020-flatland-starter-kit

ℹ️ Documentation: https://flatland.aicrowd.com/getting-started/rl.html