Add getting started tag, and add it to posts

Author: amyrlam

tests/dummy/content/2018-10-15-ember-3-5-released.md

@@ -1,7 +1,8 @@
 ---
 title: Ember 3.5 Released
 author: melanie
-tags: Releases, 2018, 3, 3.5
+tags:
+  - getting-started
 responsive: true
 ---
 

tests/dummy/content/2018-10-26-the-ember-times-issue-70.md

@@ -4,11 +4,8 @@ authors:
   - melanie
   - jen
 excerpt: This is a test... This week we have an Ember standard for i18n 🌍, more convenient **transitions** through your Ember apps with the **new Router Helpers & Element Modifiers RFC**, artisan ☕️ deprecations for **setting** your **component managers**, a **new version of Ember**, an exciting new Readers' Question 🤔 on the future of controllers, using GraphQL in Ember 💥, and more!
-tags: 
-  - Newsletter
-  - Ember.js Times
-  - Ember Times
-  - 2018
+tags:
+  - getting-started
 alias : "blog/2018/10/26-the-ember-times-issue-70.html"
 responsive: true
 ---

tests/dummy/content/2018-11-02-the-ember-times-issue-71.md

@@ -2,7 +2,8 @@
 title: The Ember Times - Issue No. 71
 author: melanie
 #author: Chris Ng, Jessica Jordan, Ryan Mark, Kenneth Larsen, Alon Bukai, Amy Lam
-tags: Recent Posts, Newsletter, Ember.js Times, Ember Times, 2018
+tags:
+  - getting-started
 alias : "blog/2018/11/02-the-ember-times-issue-71.html"
 meta:
   responsive: true

tests/dummy/tag/getting-started.md

@@ -0,0 +1,6 @@
+---
+name: Getting Started
+image:
+imageMeta:
+---
+A description for the Getting Started tag