fixed HTML validation errors found after JS insertion

Moved the `aria` attributes from the `a` to the `li` and changed the `role` to `option` as per @masterbee request.

Also fixed the `module` code because it was calling a `header` inside a `header`.

Still not validating at 100% because of the mobile menu but according to @masterbee we would need to rewrite this function to get this to validate.

Hope this is ok for my first JS change in WET.
This should not be changed to option. It must be of type menuitem.