Inline call to GovspeakHtmlConverter
Inline call to GovspeakHtmlConverter

The GovspeakToHTMLRenderer was calling the GovspeakHtmlConverter and
assigning the result to the `body` key of the `attributes` hash. We
can avoid that indirection by calling GovspeakHtmlConverter directly.

alphagov/manuals-publisher,alphagov/manuals-publisher,alphagov/manuals-publisher