fix: set author to string

src/manifest.json

@@ -3,10 +3,7 @@
   "version": "__VERSION__",
   "manifest_version": 2,
   "description": "__MSG_extDescription__",
-  "author": {
-    "name": "Gerald",
-    "url": "http://gerald.top"
-  },
+  "author": "Gerald",
   "homepage_url": "https://violentmonkey.github.io/",
   "icons": {
     "16": "public/images/icon16.png",