Refs https://github.com/TryGhost/Team/issues/459
- Updated styles for Facebook, Twitter and Google
- Added mockup for tweets, posts, and Google search results
- Got rid of browser mockup on desktop preview
- Changed button-group active style from blue to black
refs https://github.com/TryGhost/Team/issues/459
- the SERP description was not falling back to the server-side generated `excerpt` field on the post
- removed outdated dynamic description generation from markdown card, should be replaced with dynamic description generation from mobiledoc if needed
refs https://github.com/TryGhost/Team/issues/451
- Added mobile view to the post preview modal
- Replaced tabs text with icons
- Moved back button and added publish button
- Changed copy-link design to be aligned with link preview in portal
- Changed layout for social previews
- Added images to the Twittr and Facebook previews
- Added labels to the social previews
- Changed styling for the "Preview post" button in editor
refs https://github.com/TryGhost/Team/issues/451
- disabled email tab when previewing a page (pages can't be emailed)
- added share preview url footer to browser tab
- added send preview footer to email tab
- added first pass at social tab contents
