Function config::get_or_create_sub_module

pub fn get_or_create_sub_module<'lua>(
    lua: &'lua Lua,
    name_path: &str,
) -> Result<Table<'lua>>

Given a name path like foo or foo.bar.baz, sets up the module registry hierarchy to instantiate that path. Returns the leaf node of that path to allow the caller to register/assign functions etc. into it