ludic/changes/reducer-reads.md

bump: minor type: feat A reducer may read other states. reducer Wallet on Buy(w: mut Wallet, s: Shop, a: Buy) writes its own state and reads the ones declared between it and the action, supplied by the drain like its own. What only becomes known inside the drain - a value another reducer just set, the map in play, where the save lives - no longer has to be faked into the action, and a verb that reads several systems while it changes one is a reducer instead of an act. A second state to WRITE is still refused, now with the way out in the message (examples/actions/reads.ludic).