an option to play a song in an html export?

Development Export
1

:book:

2

I am not quite sure what you mean.

If you want to add a link, use the html syntax for a file link:

<a href="%_filename_ext%">%title%</a>

There is a sample html export, you may use this a source for the amendment.

3

There are some export-html-scripts in the configuration archive that can play mp3s:
/t/1495/1