Update sites.yml
Update sites.yml
Added a guide helper.

Think it's more appropriate to move sorts done in
'built-using-middleman.html.erb' to a helper in guide_helpers.rb, seemed
repeating.
Minor refactor built-using-middleman.html.erb
Fix typo
Merge pull request #348 from limekin/master

Update sites.yml
Merge pull request #347 from philipjoubert/patch-1

Update sites.yml
Fix typo blogs to blog in built-using-middleman.html.erb
Merge pull request #349 from limekin/master

Fix typo blogs to blog in built-using-middleman.html.erb
Add Bourbon and Neat

* Add Bitters files for base styles