Document DatoCMS/Snipcart workflow

[AishaBlake]

Summary

The most recent Learning team webinar walked through how to spin up and customize a new Gatsby site using DatoCMS and Snipcart. I discussed this with Marcy and we decided to include the writeup in the docs as a tutorial. This ties into #19768 and is meant to be approachable for non-devs as well as developers.

Motivation

This is a shift in focus from the originally planned material but I think it's timely and gives us a way to support some of the people whose businesses are struggling because of the pandemic. The tutorial should provide a lightweight, low-cost way for folks to get started with e-commerce.

Steps to resolve this issue

Draft the documents

• Copy the tutorial over, adjusting anything not compliant with the style guide.
• Add the article to the docs sidebar under the [parent doc] section.
• Write everything up in a blog post which points back the tutorial as well as the YouTube video.
• PR for the tutorial chore(tutorial):Add DatoCMS/Snipcart tutorial #22561
• PR for the blog post

[AishaBlake]

Decided against the blog post but I still think it's a good idea for future such tutorials/webinars!