Koha-howto integration

[joubu]

It would be great to get koha-howto (https://github.com/joubu/koha-howto) integrated by default into the devbox.
But actually I have no idea how to process.
The git clone could be enough, but it would be handy to have the cp (+ add to .gitignore) or a trick with plack config files.
I do not think one of these two solutions are perfect since we will need to modify Koha core files.