fix(package): Update funding format

Author: fb55

package.json

@@ -3,7 +3,9 @@
     "description": "a simple bitfield, compliant with the BitTorrent spec",
     "version": "3.0.0",
     "author": "Felix Boehm <[email protected]>",
-    "funding": "https://github.com/sponsors/fb55",
+    "funding": {
+        "url": "https://github.com/sponsors/fb55"
+    },
     "sideEffects": false,
     "main": "lib/index.js",
     "types": "lib/index.d.ts",