Decorative railways (as a land-based analogue of ships)

[Mirolit 185]

I think that for decorative ships it is worth adding land analogues, which (like ships) will change depending on the era. For example, at the game start, these can be caravans (2-3 same tiny wagons moving one after another), and when civilization discovers railway technology, all caravans within civilization will be replaced by railway tracks connecting provinces. In modern scenarios, train sprites can be raplaced with high-speed maglev (or airplanes, for example)

Probably, the implementation of this will take even more time than adding ships, but the game map will look even more lively and non-static