Update doc after layout simplification

Author: regisphilibert

README.md

@@ -19,11 +19,11 @@ module:
     - path: github.com/theNewDynamic/hugo-module-tnd-netlify-cms
 ```
 1. Create a page where your Netlify CMS dasboard should live.
-2. Add the `netlifycms` layout to it through Front Matter.
+2. Add the `netlifycms` type to it through Front Matter.
 3. Add the `netlifycms_config` output format to it through Front Matter (alongside HTML):
 ```yaml
 Title: Your CMS
-layout: netlifycms
+type: netlifycms
 outputs:
   - HTML
   - netlifycms_config