updating the blog template to include the new social image bit.

CONTRIBUTING.md

@@ -36,6 +36,8 @@ author:
  bio: ""
  image: /users/
 date: ''
+images:
+  - /blog-images/
 post:
 	title: ""
 	image: /blog-images/
@@ -48,6 +50,7 @@ post:
 - Your **bio** will be displayed directly under your name, so please keep this to 60 characters or less. If you would like to leave this blank, you may do so. 
 - Your author **image** should be appropriate for an all-audiences website and added to `./static/users/` in .png format. The file will serve from `/users/`, so do not change the beginning of this path. 
 - The **date** is the date (in YYYY-MM-DD format) you want to see the blog post published, but we cannot always guarantee a publishing timeline. 
+- The **images** image is the social image that's used, and should be put in `./static/blog-images/`
 - The post **title** should match the above.
 - A post **image** should be included, and will be displayed both on the [almalinux.org/blog/](almalinux.org/blog/) feed, and as the header image on the full-page blog post. Use this tempalte to get started: `./static/blog-images/blog_images_template.svg`
   - Your image should not violate any trademarks or copyrights, and should be relevant to blog content. Once created, a PNG version of your image should be placed in `./static/blog-images/` The file will serve from `/blog-images/`, so do not change the beginning of this path.