Add extrinsic record

extrinsic_record.json

@@ -0,0 +1,4 @@
+{
+  "extrinsic": "7515869-24",
+  "hotkey": "5FEhmShdTaPuMRCTJ88y4EN99yv6CkPDc3yQxfEYtp1U8Gdd"
+}