style(gatsby): Include node types (#4033)

This PR will have various follow-ups to a refactor of the Gatsby SDK. To have more focused and smaller PRs, extracting the styling to this one.

Author: iker-barriocanal

packages/gatsby/tsconfig.json

@@ -4,6 +4,6 @@
   "exclude": ["dist"],
   "compilerOptions": {
     "rootDir": ".",
-    "types": ["jest"]
+    "types": ["node", "jest"]
   }
 }