Hugo: Update multilingual example

[digitalcraftsman]

The current multilingual example used workarounds to create an internationalized website. But since Hugo has native i18n support (as part of Hugo v0.17) it would be consquently to update the example as well.

[aubort]

I'd be happy to contribute, if it can wait a week or two before being contributed.

[aubort]

I have started to work on this today and will update the code here as I make progress.

[aubort]

Just a quick update on this, I've updated the code and have a very basic version of multilingual site based on the previous example.
I've updated the branch (https://github.com/aubort/hugo/tree/multilingual-example/examples/multilingual).

Happy to hear your comments/feedback. I am not sure how complex this example should be, but I still want to add the multilingual menu because I think it is important.