Add way to assign custom notification .mp3

[MoshirMoshir]

It would be really cool if you were somehow able to set the .mp3 sounds to variables that the user can change in the settings page to their own .mp3

I wanted to do this but the extent of my knowledge just let me take the source code, replace the sound with my own, and then compile it with vscode really inefficiently (generated a bunch of extra files not in your release) after adding the file below to get it to work (it would give me a package error NU1101 without the Nuget.config).

Nuget.config:

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <packageSources>
      <clear /> <!-- (optional) this is for clear sources like default Offline repo -->
      <add key="nuget.org" value="https://api.nuget.org/v3/index.json" protocolVersion="3" />
  </packageSources>
</configuration>