Fix YAML code block formatting in docs (#1356)

* Fix YAML code block formatting in docs

* Add @tedmiston to contributors

website/site/content/docs/authentication-backends.md

@@ -24,8 +24,8 @@ To use it in your own project, follow these steps:
       accept_roles: #optional - accepts all users if left out
         - admin
         - editor
-     
     ```
+
 3. Optionally, you can assign roles to users in your Netlify dashboard, and then limit which
    roles can access the CMS by defining the `accept_roles` field in the `config.yml` example above.
    Otherwise `accept_roles` can be left out, and all Netlify Identity users on your site will have access.
@@ -50,11 +50,12 @@ To enable it:
 1. Follow the authentication provider setup steps in the [Netlify
    docs](https://www.netlify.com/docs/authentication-providers/#using-an-authentication-provider).
 2. Add the following lines to your `config.yml` file:
-   ```yaml
-   backend:
-     name: github
-     repo: owner-name/repo-name # Path to your Github repository
-   ```
+
+    ```yaml
+    backend:
+      name: github
+      repo: owner-name/repo-name # Path to your Github repository
+    ```
 
 ### External OAuth Clients