New operators for Palette

With these it would be easier to create more complicated timelines
without repeating yourself over and over again.

MuzikaGromche/Plugin.cs

@@ -263,6 +263,28 @@ namespace MuzikaGromche
             }
             return new Palette(colors);
         }
+
+        public static Palette operator +(Palette before, Palette after)
+        {
+            return new Palette([.. before.Colors, .. after.Colors]);
+        }
+
+        public static Palette operator *(Palette palette, int repeat)
+        {
+            var colors = Enumerable.Repeat(palette.Colors, repeat).SelectMany(x => x).ToArray();
+            return new Palette(colors);
+        }
+
+        public Palette Stretch(int times)
+        {
+            var colors = Colors.SelectMany(color => Enumerable.Repeat(color, times)).ToArray();
+            return new Palette(colors);
+        }
+
+        public Palette Use(Func<Palette, Palette> op)
+        {
+            return op.Invoke(this);
+        }
     }
 
     public class Track