[docs][recipes] Prepare for deployment

[marcysutton]

Summary

To improve key learning workflows in the Recipes section of the docs, there should be a short, actionable recipe on preparing a site for deployment. This would include generating your site with gatsby build and adding an optional path prefix (with a quick note about why you would even need/want that option).

Recipes now follow this format:

• Requirements or prerequisites
  • Gatsby CLI
  • A Gatsby site
• Step-by-step instructions
• Relevant links to any relevant information
  • More on preparing a site for deployment

This recipe should go into the "Deploying" section of docs/docs/recipes.md, replacing the existing text. Docs URLs to gatsbyjs.org should be relative. There is a recipe template in the contributing docs: https://www.gatsbyjs.org/contributing/docs-templates/#recipes

For reference, the new recipe collection is also listed in a spreadsheet: https://docs.google.com/spreadsheets/d/1yNUQi_-3TsuDtE98hCIJQvLZ6X1YHlDmC-EJwOGxiHk/edit#gid=1252007048

[tom-raley]

I’d like to take this on if no one else has started yet!

[marcysutton]

Go for it, @tom-raley! Thanks for offering!

[marcysutton]

Closed with #15605