fix: format JSON with newline (is-a.dev Tests)

domains/saurabh-singh.json

@@ -1 +1,9 @@
-{"owner":{"username":"singhsaurabh813045","email":"singhsaurabh813045@gmail.com"},"record":{"CNAME":"singhsaurabh813045.github.io"}}
+{
+  "owner": {
+    "username": "singhsaurabh813045",
+    "email": "singhsaurabh813045@gmail.com"
+  },
+  "record": {
+    "CNAME": "singhsaurabh813045.github.io"
+  }
+}