Changing examples to use makefile

- Testing a modified version of the makefile from raylib Instead of multiple project files for examples.
- Fixed readme example

Examples/audio/audio_music_stream.cs

@@ -0,0 +1,7 @@
+using Raylib;
+using static Raylib.Raylib;
+
+public partial class Examples
+{
+    /*******************************************************************************************
+    *

Examples/audio/audio_raw_stream.cs

@@ -0,0 +1,7 @@
+using Raylib;
+using static Raylib.Raylib;
+
+public partial class Examples
+{
+    /*******************************************************************************************
+    *

Examples/audio/audio_sound_loading.cs

@@ -0,0 +1,7 @@
+using Raylib;
+using static Raylib.Raylib;
+
+public partial class Examples
+{
+    /*******************************************************************************************
+    *