Govspeak for view templates.

- Add govspeak gem
- Register govspeak as a handler for view templates ending in `.md`
This is a bit odd, we're storing `@title` in an instance variable, but then redoing the search every time this method is called.

Also, `find` take an "if none" argument.

Did you intend this perhaps?
```ruby
def title
  @title ||= govspeak.headers.find('') { |header| header.level == 1 }
end
```