Add extinctsion.is-a.dev to the domains directory

domains/extinctsion.json

@@ -0,0 +1,9 @@
+{
+    "owner": {
+        "username": "extinctsion",
+        "email": "[67048929+extinctsion@users.noreply.github.com]"
+    },
+    "records": {
+        "A": ["75.2.60.5"]
+    }
+}