Add "Suggested Topics" from discussion with Todd.
Merge "Resources" section with "Suggested Topics" section.
Add Playgrounds folder with samples.
Add literate style to basic LearningSwift playground and link to online version of the docs (not the eBooks).
Add ebook links, since main link goes to online version of the docs.
Add REPL instructions.
Add Optionals section to "Basics" playground.
Add basic prerequisites
Add scripting section.
Add Resources
Add scripting update.
Move Resources to separate doc.
Add online and ref sections.
Add resources link to resources section.
Add repl blog post with ref card.
Add headings (probably temporary) for sections.

Will probably replace headings with HTML/CSS sections.
Add updates to REPL docs from Apple REPL blog post.
Add Balloons playground from Apple.
Fix typo in REPL commands.
Add link to Swift with SpritKit demo.