How to ignore folders, if not needed like 404 or others

## Summary

I have no need for a 404 page, because gridsome sits on a subfolder and when a path is not found, nginx will cover that for me.

Furthermore, I followed this [tutorial](https://www.storyblok.com/tp/gridsome-multilanguage-website-tutorial) for using a headless CMS with gridsome. However, they implement a live Editor in the `/src/pages/Editor.vue` path.

After running the build command, the editor page is obviously included as well. How could I remove this page, when not needed? Also very important, because I don't want to precache the path with a Service Worker.

Thanks! And I love this project so much! Well done!

Edit: To be fair, I came up with one solution, by moving editor file to `/template` and then by creating the page programmatically I can change it via the `NODE_ENV` state.

Start with the page-generation behavior around /src/pages/Editor.vue and the programmatic page creation approach described in the edit. Check how Gridsome handles pages moved outside /src/pages during a production build, including generated routes and service-worker precaching. Done means a documented or supported way to exclude an unwanted page such as 404 or Editor.

Written by the indexing model from the issue text.