Add option to save to external storage (microSD card)

[aramaicus]

I would like to suggest adding an option for users to save music files to external storage (microSD card) in the project.

Many popular apps such as YT Music, AntennaPod, and Youtube already offer this feature, which can greatly enhance user flexibility and convenience.

Implementing this functionality would provide users with more control over their storage preferences.

Here's how it's implemented in AntennaPod:

Thank you for considering this enhancement.