explicitly add acorn as a dependency

Author: tsnobip

package-lock.json

@@ -23,6 +23,7 @@
     "@rescript/core": "^1.3.0",
     "@rescript/react": "^0.12.0-alpha.3",
     "@rescript/tools": "^0.5.0",
+    "acorn": "^8.11.3",
     "codemirror": "^5.54.0",
     "docson": "^2.1.0",
     "escodegen": "^2.1.0",
@@ -72,4 +73,4 @@
     "simple-functional-loader": "^1.2.1",
     "tailwindcss": "^3.3.3"
   }
-}
+}