add core dep

Author: jfrolich

rewatch/testrepo/packages/with-dev-deps/package.json

@@ -5,5 +5,8 @@
     "rescript"
   ],
   "author": "",
-  "license": "MIT"
+  "license": "MIT",
+  "dependencies": {
+    "@rescript/core": "*"
+  }
 }