chore: add funding to package.json (#130)

Ref: expressjs/discussions#356

Author: Phillip9587

package.json

@@ -9,6 +9,10 @@
   ],
   "license": "MIT",
   "repository": "jshttp/http-errors",
+  "funding": {
+    "type": "opencollective",
+    "url": "https://opencollective.com/express"
+  },
   "dependencies": {
     "depd": "~2.0.0",
     "inherits": "~2.0.4",