Do you mean by dockable that oher players can dock at your ship?
That takes alota work to be "dockable".. but not much to be flyable..
In MP dockable player ships are handled by the new Hooks.. either the plugin version or M0tah's Flak one
will do it.. i haven't done it as yet.. but its very "do-able"
as for flyable.. make a new entry below the original with the sufix pl_ (not needed but helps!)
ie: nickname = pl_rh_battleship
and alter that one to your liking.. add the weps/shields ect like you would a standard fighter
use Trader shields for the shield link!... and beware of its cloak! as that can cause problems too
(the RH BS can cloak in SP storyline) unless your "hooked" for that as well 
make a goods entry with HCMP open.. in fact do it all with HCMP open.. and make shure not to miss anything
Ive made all ships flyable in my mod.. this one was the tricky one if i can recall 