Apply full filename in links for other templates

Applied change from previous commit (re: #309 and #303) to the classic
and linear templates.

I’m not sure if some people have a preference for just showing the
basename, but that option isn’t really compatible with multi-directory
sites. For single-folder sites (say, if everything is in `app/`, and
you don’t want `app/` at the front of all your links) you can get
around it simply by running docco from within the folder containing the
files (at least with the CLI).