docs(fix): revert prettier formatting on markdown files (#1612)

Prettier formatting our markdown files is causing bugs because of the
differences between Gatsby's parser and Prettier's. Also, Prettier
formats the inline code-blocks containing example CMS configs, but the
formatting it uses doesn't really make much sense or match the suggested
CMS config style.

It doesn't actually make much sense to format the docs anyway, since we
use the CMS itself to edit/generate them.

website/content/docs/add-to-your-site.md

@@ -60,15 +60,15 @@ npm install netlify-cms --save
 Then import it (assuming your project has tooling for imports):
 
 ```js
-import CMS from 'netlify-cms';
+import CMS from 'netlify-cms'
 
 // Now the registry is available via the CMS object.
-CMS.registerPreviewTemplate('my-template', MyTemplate);
+CMS.registerPreviewTemplate('my-template', MyTemplate)
 ```
 
 ## Configuration
 
-Configuration will be different for every site, so we'll break it down into parts. All code snippets in this section will be added to your `admin/config.yml` file.
+Configuration will be different for every site, so we'll break it down into parts.  All code snippets in this section will be added to your `admin/config.yml` file.
 
 ### Backend
 
@@ -103,7 +103,7 @@ Netlify CMS allows users to upload images directly within the editor. For this t
 
 ```yaml
 # This line should *not* be indented
-media_folder: 'images/uploads' # Media files will be stored in the repo under images/uploads
+media_folder: "images/uploads" # Media files will be stored in the repo under images/uploads
 ```
 
 If you're creating a new folder for uploaded media, you'll need to know where your static site generator expects static files. You can refer to the paths outlined above in [App File Structure](#app-file-structure), and put your media folder in the same location where you put the `admin` folder.
@@ -112,8 +112,8 @@ Note that the`media_folder` file path is relative to the project root, so the ex
 
 ```yaml
 # These lines should *not* be indented
-media_folder: 'static/images/uploads' # Media files will be stored in the repo under static/images/uploads
-public_folder: '/images/uploads' # The src attribute for uploaded media will begin with /images/uploads
+media_folder: "static/images/uploads" # Media files will be stored in the repo under static/images/uploads
+public_folder: "/images/uploads" # The src attribute for uploaded media will begin with /images/uploads
 ```
 
 The configuration above adds a new setting, `public_folder`. While `media_folder` specifies where uploaded files will be saved in the repo, `public_folder` indicates where they can be found in the published site. This path is used in image `src` attributes and is relative to the file where it's called. For this reason, we usually start the path at the site root, using the opening `/`.
@@ -127,12 +127,14 @@ Collections define the structure for the different content types on your static
 Let's say your site has a blog, with the posts stored in `_posts/blog`, and files saved in a date-title format, like `1999-12-31-lets-party.md`. Each post begins with settings in yaml-formatted front matter, like so:
 
 ```yaml
+---
 layout: blog
 title: "Let's Party"
 date: 1999-12-31 11:59:59 -0800
-thumbnail: '/images/prince.jpg'
+thumbnail: "/images/prince.jpg"
 rating: 5
-...
+---
+
 This is the post body, where I write about our last chance to party before the Y2K bug destroys us all.
 ```
 
@@ -140,18 +142,18 @@ Given this example, our `collections` settings would look like this in your Netl
 
 ```yaml
 collections:
-  - name: 'blog' # Used in routes, e.g., /admin/collections/blog
-    label: 'Blog' # Used in the UI
-    folder: '_posts/blog' # The path to the folder where the documents are stored
+  - name: "blog" # Used in routes, e.g., /admin/collections/blog
+    label: "Blog" # Used in the UI
+    folder: "_posts/blog" # The path to the folder where the documents are stored
     create: true # Allow users to create new documents in this collection
-    slug: '{{year}}-{{month}}-{{day}}-{{slug}}' # Filename template, e.g., YYYY-MM-DD-title.md
+    slug: "{{year}}-{{month}}-{{day}}-{{slug}}" # Filename template, e.g., YYYY-MM-DD-title.md
     fields: # The fields for each document, usually in front matter
-      - { label: 'Layout', name: 'layout', widget: 'hidden', default: 'blog' }
-      - { label: 'Title', name: 'title', widget: 'string' }
-      - { label: 'Publish Date', name: 'date', widget: 'datetime' }
-      - { label: 'Featured Image', name: 'thumbnail', widget: 'image' }
-      - { label: 'Rating (scale of 1-5)', name: 'rating', widget: 'number' }
-      - { label: 'Body', name: 'body', widget: 'markdown' }
+      - {label: "Layout", name: "layout", widget: "hidden", default: "blog"}
+      - {label: "Title", name: "title", widget: "string"}
+      - {label: "Publish Date", name: "date", widget: "datetime"}
+      - {label: "Featured Image", name: "thumbnail", widget: "image"}
+      - {label: "Rating (scale of 1-5)", name: "rating", widget: "number"}
+      - {label: "Body", name: "body", widget: "markdown"}
 ```
 
 Let's break that down:
@@ -202,14 +204,14 @@ The entries for any collection can be filtered based on the value of a single fi
 
 ```yaml
 collections:
-  - name: 'posts'
-    label: 'Post'
-    folder: '_posts'
+  - name: "posts"
+    label: "Post"
+    folder: "_posts"
     filter:
       field: language
       value: en
     fields:
-      - { label: 'Language', name: 'language' }
+      - {label: "Language", name: "language"}
 ```
 
 ## Authentication