README.effects should mention that effect values are cumulative
omero points out in https://forum.freeciv.org/f/viewtopic.php?p=108421#p108421 that README.effects does not explain how effect values are cumulative.
omero points out in https://forum.freeciv.org/f/viewtopic.php?p=108421#p108421 that README.effects does not explain how effect values are cumulative.