Missing field formatter configuration schema

At the moment, the module is missing configuration schema. Enabling the configuration inspector module shows these errors related to the audiofield module:

content.field_media_audio_file.settings.audio_player_jplayer_theme [missing schema]
content.field_media_audio_file.settings.audio_player_wavesurfer_audiorate [missing schema]

This prevents the field formatter settings from being translated amongst other things.

The solution to this issue is to create configuration schema for the field formatter according to the instructions here: https://www.drupal.org/docs/8/creating-custom-modules/creating-custom-fi...

I will add a patch containing the schema.

Note that users will need to be informed that need to re-save the field formatter settings for any formatters using the audiofield in order to rectify mismatched configuration type errors.