WIP add turbulence_closure test to docs

docs/users_guide/ocean/test_groups/turbulence_closure.rst

@@ -0,0 +1,22 @@
+.. _ocean_turbulence_closure:
+
+turbulence_closure
+==================
+
+The ``turbulence_closure`` test group implements studies of the surface layer
+evolution under different kinds of surface forcing for different turbulence
+closures.
+
+config_LES_mode = .true.
+config_use_two_equation_turbulence_model = .true.
+config_two_equation_model_choice = 'omega'
+config_use_cvmix = .false.
+config_two_equation_length_min = 0.1
+config_two_equation_tke_min = 1e-10
+config_two_equation_psi_min = 1e-10
+config_tke_ini = 1.0e-30
+config_LES_noise_enable = .true.
+config_LES_noise_max_time = 150
+config_LES_noise_min_level = 5
+config_LES_noise_max_level = 45 
+config_LES_noise_perturbation_magnitude = 1e-4