Initialise this module. As we pass in the initialisation state object (current), we could/should consider making this set the level to basic, e.g. current%level = init_level_list%basic
subroutine init_gs2_init
implicit none
if (initialized) return
initialized = .true.
#include "gs2_init_level_array.inc"
end subroutine init_gs2_init