chore: Create FUNDING.json for OP RPF (#335)

IP Shipyard is applying for Optimism's retroactive public funding round for developer tooling. This PR adds a json file to associate this repo with IP Shipyard's application.

Author: p-shahi

FUNDING.json

@@ -0,0 +1,5 @@
+{
+  "opRetro": {
+    "projectId": "0x7f330267969cf845a983a9d4e7b7dbcca5c700a5191269af377836d109e0bb69"
+  }
+}