Corrected images.

Despite having .svg extensions, they were png images.
Renamed to correct this.
Added listeners and functions for rolling the die.

Renamed button#generat to button#roll and removed [value]
Re-added images after correcting file extensions
Moved index.html to index.php

Since I require .php in Apache for some reason.
Added styles to index.css for #die.

Defaults to display:none before roll

Has default style when data-roll is set.

Value of roll attribute cylces background images, showing what was rolled.

Re-added index.php, which I forgot to add when it was renamed from index.html
Corrected style for #die.

data-rolled attribute is correctly detecting values.
background-image is correctly being set (had forgotten the '../')