Split Enums, Structs & Classes into own files

Raylib-cs/CameraProjection.cs

@@ -0,0 +1,9 @@
+namespace Raylib_cs
+{
+    /// <summary>Camera projection</summary>
+    public enum CameraProjection
+    {
+        CAMERA_PERSPECTIVE = 0,
+        CAMERA_ORTHOGRAPHIC
+    }
+}