Mainly by @rap1412. I added the terrain menu. Click on any tile to open it. Press X to hide it. New instructions for @rap1412: When opening the terrain menu, 4 different buttons can appear. Make them work as explained here: If it's ground: only the build button appears. Clicking on this will replace the tile by a building tile (I already added one). If it's water or vegetation: only the terraform button appears. Clicking on this will replace the tile by a ground tile. If it's a building: two buttons appear: demolish and upgrade. Clicking on the demolish buttons replace the tile by a ground tile. Clicking on the upgrade button will do nothing for the moment.
