frequency doubling

some tech is now only 50% likely to show up
  I choose about 25 tech that don't effect game play as much, and dropped them down to 50% frequency

reset on experiment menu should now clear power ups and bullets

fixed bug with no heals

js/simulation.js

@@ -496,6 +496,7 @@ const simulation = {
     fpsInterval: 0, //set in startGame
     then: null,
     startGame(isBuildRun = false) {
+        simulation.clearMap()
         if (!isBuildRun) { //if a build run logic flow returns to "experiment-button").addEventListener
             document.body.style.cursor = "none";
             document.body.style.overflow = "hidden"