[Minimap Suggestion] Kreposts and Donjons#40

Kreposts and Donjons should also get their own unique icon in the minimap like Castles.

Another one to consider is towers, designing these to make them unique and interprtetable on small devices would be quite difficult though.

We have discussed Towers, Krepost, Towers, BBTs and walls (I.e. all defensive structures) previously - I think this could make sense, but perhaps will be moved to their own minimap mode if it proves to be too intrusive.