Update gitlab-com pricing page with automated information.

See also #1446 (closed).

Review App: https://cs-gitlab-com-pricing.about.gitlab.com/gitlab-com/

gitlab_com is already used for comparisons that compare GitLab.com and GitHub.com, among other things, so maybe the attribute for excluding a feature from the GitLab.com pricing page should be called gitlab_com_plans?

I'm also not sure how to handle Silver/Gold, as I think both have EEP features and the main difference is the support time and the build minutes?

cc: @mydigitalself