Fixing typo.

Adding missing `do`s for blocks.
Merge pull request #216 from polarblau/patch-1

Fixing typo.
Update built-using-middleman.html.erb

Adding http://www.startexploding.com
Merge pull request #218 from startexploding/master

Update built-using-middleman.html.erb
Typo fix

“current” should be “content”
Merge pull request #219 from acusti/patch-1

Typo fix
Add my site to Sites Built Using Middleman.
Merge pull request #220 from AndrewKvalheim/add-your-site

Add my site to Sites Built Using Middleman.
Merge remote-tracking branch 'upstream/master' into ja

Conflicts:
	source/frontmatter.html.markdown