Migrate netlify-cms-www site into this repo (#860)

* Add frontmatter to docs files (prep to move)

* Move docs into position for website migration

* Migrate website from netlify-cms-www

Some modifications, including most of the changes in https://github.com/netlify/netlify-cms-www/pull/58 (previously reverted).

Also updated the readme and added hugo-bin for quicker onboarding of new docs contributors.

* Remove netlify.toml

This allows separate build commands for cms-demo and netlifycms.org.

* Remove website/netlify.toml

May re-add later, but it's not doing anything for now.

* Remove unused content file

website/site/content/pages/community.md

@@ -0,0 +1,29 @@
+---
+title: Community
+layout: community
+url: /community
+
+headline: Be a part of building the CMS of the future.
+subhead: We're serious about being community driven, so everyone is welcome to join our open, bi-weekly planning sessions.
+primarycta: "[Register on Eventbrite →](https://www.eventbrite.com/e/netlify-cms-planning-session-bi-weekly-tickets-35794058994)"
+
+upcomingevent:
+  hook: The next development planning session is on
+
+howitworks: Every other week we have public development planning sessions. They're web based, last about an hour, and are geared toward contributors and those interested in contributing. Sessions currently take place every other Wednesday, 9am - 10am PT.
+
+howtojoin: |
+  **On the web:**
+
+  1. https://bluejeans.com/278173690
+
+  **By phone:**
+
+  1. [+1.408.740.7256](tel:+14087407256) (United States)
+
+      [+1.408.317.9253](tel:+14083179253) (Alternate number)
+
+      (http://bluejeans.com/numbers)
+
+  2. Enter Meeting ID: 278173690
+---