package-builder: Install the hotdoc-0.8 branch of HotDoc
Newer version of HotDoc like 0.10 break the current packages, so let's pull here the 0.8 hotdoc branch packages before pointing all the affected packages to them.
Newer version of HotDoc like 0.10 break the current packages, so let's pull here the 0.8 hotdoc branch packages before pointing all the affected packages to them.