Generate draft URLs in preview environment

[daine]

📇 User story

As a preview user, I want to be able to share and access preview URLs that are currently new and in draft in Contentful, so that I can work on creating content faster.

✅ Definition of Done

• Code reviewed
• Feature fully tested on preview environment
• No changes should be seen on the production environment

📜 Acceptance criteria

• Utilize the PREVIEW_ENV flag to make the changes only appear on the preview environment
• Consider having a webhook in contentful to automatically deploy the preview environment amplify application
• New content (which appears as "Draft") will have their own URLs in our nuxtjs router

📝 More info

Currently, if content designers change the URL or add new pages, they are able to access it by going to the home page and clicking around. The browser URL changes to reflect the current page, but if you do a hard refresh, or share the URL, you are redirected to a broken link (/index.html).