Allow for custom footsteps. Some work on footsteps to make the sound less crazy. Various other updates. Added initial documentation and credits files.

levels/2.json

@@ -21,13 +21,15 @@
             "static": true
         },
         {
-            "x": 25,
+            "x_range": [21, 29],
             "y": 0,
             "enemy_type": "goblin",
             "health": 4,
             "damage": 2,
             "attack_range": 1,
-            "movement_range": 5
+            "attack_pattern": {
+                "type": "patrol"
+            }
         },
         {
             "x": 35,
@@ -62,13 +64,15 @@
             "static": true
         },
         {
-            "x": 75,
+            "x_range": [71, 79],
             "y": 0,
             "enemy_type": "goblin",
             "health": 5,
             "damage": 2,
             "attack_range": 1,
-            "movement_range": 6
+            "attack_pattern": {
+                "type": "patrol"
+            }
         },
         {
             "x": 85,
@@ -109,10 +113,18 @@
                 "min": 2,
                 "max": 5
             }
+        },
+        {
+            "x_range": [145, 150],
+            "y": 3,
+            "sound": "coin",
+            "collectible": true,
+            "static": true
         }
     ],
     "boundaries": {
         "left": 0,
         "right": 170
-    }
+    },
+    "footstep_sound": "footstep_tall_grass"
 }