adding an option (#298)

Co-authored-by: Gregory L. Wagner <[email protected]>

Author: simone-silvestri

src/OceanSimulations/OceanSimulations.jl

@@ -85,6 +85,7 @@ function ocean_simulation(grid;
                           gravitational_acceleration = g_Earth,
                           bottom_drag_coefficient = Default(0.003),
                           forcing = NamedTuple(),
+                          timestepper = :QuasiAdamsBashforth2,
                           coriolis = Default(HydrostaticSphericalCoriolis(; rotation_rate)),
                           momentum_advection = default_momentum_advection(),
                           equation_of_state = TEOS10EquationOfState(; reference_density),
@@ -185,6 +186,7 @@ function ocean_simulation(grid;
                                               tracer_advection,
                                               momentum_advection,
                                               tracers,
+                                              timestepper,
                                               free_surface,
                                               coriolis,
                                               forcing,