Add documentation links for previous releases
Add documentation links for previous releases

balanced/PyXB,CantemoInternal/pyxb,balanced/PyXB,jonfoster/pyxb2,CantemoInternal/pyxb,pabigot/pyxb,jonfoster/pyxb2,jonfoster/pyxb-upstream-mirror,pabigot/pyxb,jonfoster/pyxb-upstream-mirror,jonfoster/pyxb2,balanced/PyXB,jonfoster/pyxb-upstream-mirror,CantemoInternal/pyxb