docs: improve virsh domxml-*-native command docs
docs: improve virsh domxml-*-native command docs

* tools/virsh.pod: improve virsh man page for domxml-from-native and
domxml-to-native commands.

Signed-off-by: Alex Jia <e236faec8cb8371bfb245ba3769a84afc9a11438@redhat.com>

libvirt/libvirt,jfehlig/libvirt,wiedi/libvirt,shugaoye/libvirt,iam-TJ/libvirt,eskultety/libvirt,rmarwaha/libvirt,andreabolognani/libvirt,trainstack/libvirt,libvirt/libvirt,bjzhang/libvirt,novel/fbsd-libvirt,wiedi/libvirt,jeckersb/libvirt,VenkatDatta/libvirt,novel/fbsd-libvirt,wiedi/libvirt,zippy2/libvirt,eskultety/libvirt,novel/fbsd-libvirt,rmarwaha/libvirt,dumbbell/libvirt,siboulet/libvirt-openvz,rlaager/libvirt,novel/fbsd-libvirt,danwent/libvirt-ovs,wiedi/libvirt,rlaager/libvirt,warewolf/libvirt,taget/libvirt,danwent/libvirt-ovs,dumbbell/libvirt,emaste/libvirt,siboulet/libvirt-openvz,danwent/libvirt-ovs,jardasgit/libvirt,rmarwaha/libvirt1,jardasgit/libvirt,trainstack/libvirt,elmarco/libvirt,novel/fbsd-libvirt,rmarwaha/libvirt1,cbosdo/libvirt,dumbbell/libvirt,foomango/libvirt,libvirt/libvirt,jardasgit/libvirt,iam-TJ/libvirt,rlaager/libvirt,fabianfreyer/libvirt,eskultety/libvirt,zhlcindy/libvirt-1.1.4-maintain,iam-TJ/libvirt,rmarwaha/libvirt1,cbosdo/libvirt,jeckersb/libvirt,jeckersb/libvirt,jfehlig/libvirt,siboulet/libvirt-openvz,foomango/libvirt,datto/libvirt,iam-TJ/libvirt,rmarwaha/libvirt1,crobinso/libvirt,cbosdo/libvirt,dumbbell/libvirt,elmarco/libvirt,warewolf/libvirt,emaste/libvirt,andreabolognani/libvirt,zhlcindy/libvirt-1.1.4-maintain,jardasgit/libvirt,zippy2/libvirt,eskultety/libvirt,elmarco/libvirt,trainstack/libvirt,wiedi/libvirt,crobinso/libvirt,nertpinx/libvirt,novel/fbsd-libvirt,nertpinx/libvirt,olafhering/libvirt,iam-TJ/libvirt,cbosdo/libvirt,andreabolognani/libvirt,agx/libvirt,shugaoye/libvirt,siboulet/libvirt-openvz,taget/libvirt,bjzhang/libvirt,zippy2/libvirt,emaste/libvirt,agx/libvirt,warewolf/libvirt,fabianfreyer/libvirt,elmarco/libvirt,danwent/libvirt-ovs,olafhering/libvirt,crobinso/libvirt,nertpinx/libvirt,warewolf/libvirt,jeckersb/libvirt,jeckersb/libvirt,elmarco/libvirt,rmarwaha/libvirt,libvirt/libvirt,zippy2/libvirt,VenkatDatta/libvirt,iam-TJ/libvirt,iam-TJ/libvirt,nertpinx/libvirt,fabianfreyer/libvirt,novel/fbsd-libvirt,emaste/libvirt,andreabolognani/libvirt,trainstack/libvirt,jfehlig/libvirt,jfehlig/libvirt,datto/libvirt,jeckersb/libvirt,eskultety/libvirt,trainstack/libvirt,olafhering/libvirt,warewolf/libvirt,warewolf/libvirt,crobinso/libvirt,emaste/libvirt,agx/libvirt,warewolf/libvirt,rmarwaha/libvirt1,foomango/libvirt,shugaoye/libvirt,emaste/libvirt,rlaager/libvirt,taget/libvirt,jeckersb/libvirt,fabianfreyer/libvirt,rmarwaha/libvirt1,zhlcindy/libvirt-1.1.4-maintain,shugaoye/libvirt,datto/libvirt,trainstack/libvirt,taget/libvirt,wiedi/libvirt,novel/fbsd-libvirt,dumbbell/libvirt,olafhering/libvirt,novel/fbsd-libvirt,rmarwaha/libvirt,bjzhang/libvirt,trainstack/libvirt,zhlcindy/libvirt-1.1.4-maintain,bjzhang/libvirt,datto/libvirt,VenkatDatta/libvirt,VenkatDatta/libvirt,foomango/libvirt,danwent/libvirt-ovs,agx/libvirt,rmarwaha/libvirt,cbosdo/libvirt,rlaager/libvirt,VenkatDatta/libvirt,foomango/libvirt,datto/libvirt,nertpinx/libvirt,taget/libvirt,emaste/libvirt,fabianfreyer/libvirt,agx/libvirt,jardasgit/libvirt,zhlcindy/libvirt-1.1.4-maintain,bjzhang/libvirt,rmarwaha/libvirt,andreabolognani/libvirt,wiedi/libvirt,dumbbell/libvirt,siboulet/libvirt-openvz,shugaoye/libvirt