Discourse comments

Add comments in docs as Discourse topics https://meta.discourse.org/t/embedding-discourse-comments-via-javascript/31963.

• Use a unique identifier for each page
• Embed discourse layout in main layout
• Create an allowed host docs.gitlab.com under Discourse https://forum.gitlab.com/admin/customize/embedding

To disable comments, in the markdown file yaml frontmatter add:

---
comments: false
---

Closes https://gitlab.com/gitlab-com/gitlab-docs/issues/44