Update code snips for new viscosity inputs

docs/source_docs/user_guide/inputs/fluid_model.rst

@@ -176,6 +176,7 @@ are not solved.
    mfix.advect_enthalpy = 0
    mfix.solve_species   = 0
 
+
    # Fluid model settings
    # -----------------------------------------------------------------------
    fluid.solve = fluid0
@@ -183,6 +184,7 @@ are not solved.
    fluid.viscosity.molecular = constant
    fluid.viscosity.molecular.constant = 1.8e-5
 
+
    # Initial Conditions
    # -----------------------------------------------------------------------
    ic.regions = full-domain
@@ -192,6 +194,7 @@ are not solved.
 
    ic.full-domain.fluid0.velocity  =  0.0  0.0  0.0
 
+
    # Boundary Conditions
    # -----------------------------------------------------------------------
    bc.regions = inlet  outlet
@@ -285,6 +288,7 @@ thermodynamic pressure for the system.
    mfix.advect_enthalpy = 1
    mfix.solve_species   = 0
 
+
    # Fluid model settings
    # -----------------------------------------------------------------------
    fluid.solve = fluid0