- Thinner and more elegant fonts on landing page.
- Removed "Overview" menu item, shortened "Documentation" to "Docs".
- Replaced jumbotron logo+title with motivational text.
- Removed "View details" buttons on landing page, make features clickable
  instead.
- Introduced testimonial quote section on landing page.
- Introduced "Open Source" section on landing page.
- Refactored overall jumbotron layout/content.
- Removed PromCon 2016 button.
- Changed documentation font to smaller size.
- Adjusted header font sizes and weights.
- Made code blocks look cooler, with orange left border.
- Don't wrap long lines in code blocks.
- Harmonized background colors between pre, code, and toc.
- Aligned the navbar Prometheus logo with the docs menu.