chore: ➕ Add missing graphql dependency

Author: pklaschka

package-lock.json

@@ -45,6 +45,7 @@
     ]
   },
   "devDependencies": {
+    "graphql": "^15.5.2",
     "graphql-markdown": "^6.0.0",
     "prettier": "^2.3.2"
   }