Rewrite rubymotion guide from HAML to Markdown (#1059)

Signed-off-by: Takuya Noguchi <[email protected]>

source/guides/rubymotion.html.md

@@ -0,0 +1,34 @@
+## How to use Bundler with RubyMotion
+
+If you don't have a RubyMotion app yet, generate one.
+
+~~~
+$ motion create myapp
+$ cd myapp
+~~~
+
+You'll need to create a Gemfile. Here we're using bubblewrap.
+
+~~~ruby
+gem 'bubble-wrap'
+~~~
+
+Then, set up your Rakefile to require your bundled gems at compile time.
+Add this to the top of the file, right beneath the line `require 'motion/project'`
+
+~~~ruby
+require 'bundler'
+Bundler.require
+~~~
+
+Next, install your dependencies:
+
+~~~
+$ bundle install
+~~~
+
+Now you can just compile your app as normal.
+
+~~~
+$ bundle exec rake
+~~~