refactor: export Girsanov_transform

Author: AayushSabharwal

src/ModelingToolkit.jl

@@ -307,7 +307,7 @@ export isinput, isoutput, getbounds, hasbounds, getguess, hasguess, isdisturbanc
        hasunit, getunit, hasconnect, getconnect,
        hasmisc, getmisc, state_priority
 export liouville_transform, change_independent_variable, substitute_component,
-       add_accumulations, noise_to_brownians
+       add_accumulations, noise_to_brownians, Girsanov_transform
 export PDESystem
 export Differential, expand_derivatives, @derivatives
 export Equation, ConstrainedEquation