Added .idea to gitignore, first pass at adding intregrated pathfindiing support using redblobgames.com tutorials as reference

lib/cyberarm_engine/pathfinding/graph.rb

@@ -0,0 +1,15 @@
+module CyberarmEngine
+  module Pathfinding
+    class Graph
+      Location = Data.define(:x, :y, :z, :cost)
+
+      def initialize(edges: {})
+        @edges = edges
+      end
+
+      def neighbors(location)
+        @edges[location]
+      end
+    end
+  end
+end