feat: add temporary sprite for encounters

sonic-radiance.love/assets/sprites/encounter.lua

@@ -0,0 +1,18 @@
+return {
+  metadata = {
+    height      = 24,
+    width       = 32,
+    defaultAnim = "default",
+    ox = 8,
+    oy = 24
+  },
+  animations = {
+    ["default"] = {
+      startAt     = 1,
+      endAt       = 8,
+      loop        = 1,
+      speed       = 4,
+      pauseAtEnd  = false,
+    },
+  }
+}