Switch to standard funding notice (#733)

Author: t3rminus

package.json

@@ -15,8 +15,7 @@
     "start": "nps",
     "test": "nps test",
     "precommit": "lint-staged && npm start validate",
-    "prepublish": "npm start validate",
-    "postinstall": "node -e \"console.log('\\u001b[35m\\u001b[1mUsing react-final-form at work? You can now donate to our open collective:\\u001b[22m\\u001b[39m\\n > \\u001b[34mhttps://opencollective.com/final-form/donate\\u001b[0m')\""
+    "prepublish": "npm start validate"
   },
   "author": "Erik Rasmussen <[email protected]> (http://github.com/erikras)",
   "license": "MIT",
@@ -123,6 +122,10 @@
     "type": "opencollective",
     "url": "https://opencollective.com/final-form"
   },
+  "funding": {
+    "type": "opencollective",
+    "url": "https://opencollective.com/final-form"
+  },
   "dependencies": {
     "@babel/runtime": "^7.8.3",
     "ts-essentials": "^5.0.0"