add cast times and cooldowns

src/game.js

@@ -50,6 +50,10 @@ export default class Game {
     this.#terrains = this.#terrains.filter((t) => t.id != terrain.id)
   }
 
+  secToTick(sec) {
+    return Math.floor(this.tickRate * sec)
+  }
+
   spawn(object) {
     if (object instanceof Entity) { this.spawnEntity(object) }
     else if (object instanceof Terrain) { this.addTerrain(object) }