Marker-Based audio (mp3) is not working

[gciandro13]

Hi, in marker-based experience i can not load any mp3 audio content (the message for unsupported format is shown).

Also another bug from the page "Get Your Shareable Link" after github publication: the back button seems not working.

I will try to fix it after the release @nicolocarpignoli

[nicolocarpignoli]

Now that i'm thinking better about this, back button bug will be fixed with #70

Instead the other one needs a separate fix.

[gciandro13]

Ok so i will look only to the first point