Adds drag-and-drop file upload. I decided not to use a library for this because it's straightforward to implement using vanilla JS and we don't have to change the way we validate files.
Adds an effect hook to register relevant drag-and-drop event handlers to AudioSelectForm
Add additional validation to file-upload handling
Check that only one file was uploaded
Check that the uploaded file is a audio file
Change the file validation, so instead of returning an error array, we only return the error string.
Resolves #18
Adds drag-and-drop file upload. I decided not to use a library for this because it's straightforward to implement using vanilla JS and we don't have to change the way we validate files.
AudioSelectForm