Create FUNDING.json (#10734)

Add FUNDING.json to participate in Optimism rPGF

Co-authored-by: Adin Schmahmann <[email protected]>

Author: p-shahi

FUNDING.json

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