[htdocs] Add Code Coverage Results for Elfutils 0.168

[Lukas Berk]

Hi,

Mark Wielaard <mark@klomp.org> writes:
[...]
> Thanks for that. If you check this in could you add a link from the
> main page. Just something like:

Thanks, added and commited.

> And a coverage/README file with instructions how to regenerate
> the pages after a new elfutils release.

Added this as well.

> Ideally we would automate this with some buildbot setup of course.
> But for now having it done by hand is better than not having it.

I don't have the means to host the master buildbot, but if you'd like help
configuring such a setup, I'd be willing to help get it up and running.

Cheers,

Lukas