Adding a titles method to return all titles

I'm not sure this is useful, but it at least lets me get my
infrastructure going.

Author: steveklabnik

Diff for: content/data_types.md

@@ -1,3 +1,6 @@
+---
+title: "Data Types"
+---
 # Data Types
 
 ## This is where it starts getting fun!

Diff for: content/datastrucs.md

@@ -1,3 +1,7 @@
+---
+title: "Data Structures"
+---
+
 # Beginner Data Structures
 
 ## Hello there!

Diff for: content/programming.md

@@ -1,3 +1,7 @@
+---
+title: "Programming"
+---
+
 # Beginner Programming
 
 ## Hello there!

Diff for: content/ruby.md

@@ -1,3 +1,7 @@
+---
+title: "Ruby"
+---
+
 # Beginner Ruby
 
 ## Hello there!

Diff for: content/shoes.md

@@ -1,3 +1,7 @@
+---
+title: "Shoes"
+---
+
 # Beginner Shoes
 
 ## Hello there!

Diff for: content/tour.md

@@ -1,3 +1,7 @@
+---
+title: "Tour"
+---
+
 # A Tour of Hackety Hack
 
 ## Welcome!

Diff for: hackety_hack-lessons.gemspec

@@ -14,4 +14,6 @@ Gem::Specification.new do |gem|
   gem.name          = "hackety_hack-lessons"
   gem.require_paths = ["lib"]
   gem.version       = HacketyHack::Lessons::VERSION
+
+  gem.add_runtime_dependency "metadown"
 end

Diff for: lib/hackety_hack/lessons.rb

@@ -1,8 +1,15 @@
-require "hackety_hack/lessons/version"
-
-puts "Nothing to see here yet..."
+require 'hackety_hack/lessons/version'
+require 'metadown'
 
 module HacketyHack
   module Lessons
+    extend self
+
+    FILE_LIST = Dir["content/*.md"]
+
+    def titles
+      FILE_LIST.collect{|file| Metadown.render(File.read(file)) }.
+                collect{|data| data.metadata["title"]}
+    end
   end
 end