Adjust playback speed outside of `tags$audio`

[barrettk]

First of all, great package! It's been quite helpful for understanding how to manipulate the playback of audio files.

I noticed that the tags$audio option had the additional controls of downloading the audio and altering the playback speed:

audio$tags Default Preview	audio$tags Options

I was looking into modifying the widget to access these controls, but just wanted to reach out and see if you had any plans to add the playback speed feature to the main howler widget?

[ashbaldry]

I didn't have any plans on including the playback rate, but if you manage to add it in, feel free to create a PR with this added in the module. If it makes it look closer to the <audio> tag then seems good to include!