Free AppVolumeHotkeys v2.1.0

With this update I have added a way to select a playback device, previously the program used the default playback device.
This is useful for setups where you have multiple playback devices and the application you want to control doesn't output to the default playback device. Your selected playback device stays saved when you close the application.

Changes since last release:
-Added ability to select a playback device
-Code cleanup/refactoring
-Updated Readme
-Update to Fody 6.0.2
-Update to Fody Costura 4.1.0
Changes since last release:
-Update to Fody 4.0.2
-Added licenses for used projects