Split Enums, Structs & Classes into own files

Raylib-cs/Sound.cs

@@ -0,0 +1,19 @@
+using System.Runtime.InteropServices;
+
+namespace Raylib_cs
+{
+    /// <summary>Sound source type</summary>
+    [StructLayout(LayoutKind.Sequential)]
+    public struct Sound
+    {
+        /// <summary>
+        /// Audio stream
+        /// </summary>
+        public AudioStream stream;
+
+        /// <summary>
+        /// Total number of frames (considering channels)
+        /// </summary>
+        public uint frameCount;
+    }
+}