"Blog Post: Move Features to Core - March 30, 2020"

Closes https://gitlab.com/gitlab-com/www-gitlab-com/-/issues/6852#note_308094552 and https://gitlab.com/gitlab-com/marketing/corporate-marketing/-/issues/2080

Review app: https://6885-blog-post-move-features-to-core-march-24-2020.about.gitlab-review.app/blog/2020/03/30/new-features-to-core/index.html

Checklist for writer

• Link to issue added, and set to close when this MR is merged
• Due date and milestone (if applicable) added for the desired publish date
• If time sensitive
  • Added ~"priority" label
  • Mentioned @rebecca to give her a heads up ASAP
• Blog post file formatted correctly, including any accompanying images
• All relevant frontmatter included
• Review app checked for any formatting issues
• Reviewed by fellow team member
• If approval before publishing is required
  • Any required internal or external approval for this blog post has been granted (please leave a comment with details)
• Assign to @rebecca for review

/label ~"blog post"