Working with submodules or import scripts?

[facusapienza21]

Right now, both here and in ODINN.jl we include submodules without declaring these as submodules. For example, SphereUDE.jl includes code with

include("types.jl")
include("utils.jl")

but none of these is a submodule by itself (that is, these scripts just have code, without the module declaration). I am not sure if this is desired or not, or if this may have impact in performance for example.