Adds block quote option

- Adds blockquote as an option
- Adds simple styling for element
Moves slides.js to /app

- Moves slides.js from /app/scripts to /app
Adds snippets and refactors

- Adds snippet obj and styling
- Refactors checking into separate function: getContentType()
- Adds example snippet to /snippets
- Adds Prism for code hi-lighting