docs: documentation for virtio packed option
docs: documentation for virtio packed option

Reviewed-by: Boris Fiuczynski <2648abdd55bfebf313fd324b464b047e6eea300e@linux.ibm.com>
Signed-off-by: Bjoern Walk <40545c009452f40d2ae0bbfbd987b332d274d328@linux.ibm.com>
Reviewed-by: Ján Tomko <4cab11cfb98d3c937327354a78eb07dbb6ee2bc6@redhat.com>
Signed-off-by: Ján Tomko <4cab11cfb98d3c937327354a78eb07dbb6ee2bc6@redhat.com>

zippy2/libvirt,nertpinx/libvirt,zippy2/libvirt,jardasgit/libvirt,olafhering/libvirt,jardasgit/libvirt,fabianfreyer/libvirt,fabianfreyer/libvirt,jardasgit/libvirt,libvirt/libvirt,zippy2/libvirt,nertpinx/libvirt,olafhering/libvirt,nertpinx/libvirt,jardasgit/libvirt,jfehlig/libvirt,libvirt/libvirt,jardasgit/libvirt,crobinso/libvirt,fabianfreyer/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,jfehlig/libvirt,nertpinx/libvirt,libvirt/libvirt,libvirt/libvirt,nertpinx/libvirt,jfehlig/libvirt,crobinso/libvirt,crobinso/libvirt,fabianfreyer/libvirt,olafhering/libvirt,zippy2/libvirt,olafhering/libvirt,crobinso/libvirt