Added initial audio library logic.

Harmonia.Core/Library/Location.cs

@@ -0,0 +1,10 @@
+namespace Harmonia.Core.Library;
+
+public class Location
+{
+    public int LocationId { get; set; }
+    public int Type { get; set; }
+    public required string Name { get; set; }
+
+    public virtual ICollection<Folder> Folders { get; set; } = [];
+}