Create deploying-to-netlify.md (#8406)

Issue #8103: this is for the "Deploy using Netlify". I tried to write a short beginner-friendly easy to follow guide for using Gatsby with Netlify.

The "Getting Started - Netlify" is copy-and-pasted of the "Deploy to S3" site, 
the introduction from the original "Deploy and Build" page.

I don't see any need for an additional "Hosting on Netlify" article.

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  Q. Which branch if I'm still not sure?
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docs/docs/deploying-to-netlify.md

@@ -0,0 +1,60 @@
+---
+title: Deploying to Netlify
+---
+
+In this guide, we'll walk through how to host & publish your next Gatsby site to [Netlify](https://www.netlify.com/).
+
+Netlify is an excellent option for deploying Gatsby sites. Netlify is a unified
+platform that automates your code to create high-performant, easily maintainable
+sites and web apps. They provide continuous deployment (Git-triggered builds),
+an intelligent, global CDN, full DNS (including custom domains), automated
+HTTPS, asset acceleration, and a lot more.
+
+Their free tier includes unlimited personal and commercial projects, HTTPS,
+continuous deployment from public or private repos and more.
+
+## Getting Started - Gatsby
+
+First, we'll want to create a new Gatsby project. If you don't already have Gatsby installed, install it:
+
+```sh
+npm install --global gatsby-cli
+```
+
+Next, we'll create a new Gatsby site:
+
+```sh
+gatsby new my-gatsby-site
+```
+
+Finally, change into the new site directory:
+
+```sh
+cd my-gatsby-site
+```
+
+**NOTE**: There is no need to build the site, Netlify can handle that for us.
+
+## Getting Started - Netlify
+
+Now, that the Gatsby site is running, we need to upload your Gatsby site to [Github](https://github.com/), [Gitlab](https://about.gitlab.com/) or [Bitbucket](https://bitbucket.org/).
+
+Now, go to Netlify and signup if you haven't already.
+We connect to Github (or Gitlab/Bitbucket) and select the repository.
+
+We can change how Netlify builds and deploys the site.
+If we change nothing, Netlify will build the `master` branch of the repository and will invoke the `gatsby build` command after we clicked deploy.
+If you would have previously build the site and pushed the build to Git, Netlify would publish the directory selected (`/public`).
+
+After Netlify now finished the build, we can see the website on the given url.
+
+## Continuous Deployment
+
+Now that your site is connected to your repository, Netlify will deploy the site and publish it whenever you push to your Git repo.
+
+## References
+
+    - [Introduction to Gatsby](https://www.gatsbyjs.org/blog/2017-05-31-introduction-to-gatsby/#deployment)
+    - [Escalade Sports: From $5000 to $5/month in Hosting With Gatsby](https://www.gatsbyjs.org/blog/2018-06-14-escalade-sports-from-5000-to-5-in-hosting/)
+    - [Why I created my blog with Gatsby and Contentful](https://www.gatsbyjs.org/blog/2017-11-09-why-i-created-my-blog-with-gatsby-and-contentful/#hosting-with-netlify)
+    - [Gatsby + Contentful + Netlify (and Algolia)](https://www.gatsbyjs.org/blog/2017-12-06-gatsby-plus-contentful-plus-netlify/#solution-netlify--gatsby)