Updating icons

ext/manifest.json

@@ -4,7 +4,19 @@
     "description":      "Yomichan Extension",
     "version":          "0.0.1",
 
-    "browser_action": {"default_icon": "icon.png"},
+    "icons": {
+        "16":  "img/icon16.png",
+        "48":  "img/icon48.png",
+        "128": "img/icon128.png"
+    },
+
+    "browser_action": {
+        "default_icon": {
+            "19": "img/icon19.png",
+            "38": "img/icon38.png"
+        }
+    },
+
     "background":   {"page": "bg/background.html"},
     "options_page": "bg/options.html",
     "permissions":  ["storage"],