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/textures/textures_srcrec_dstrec.cs

@@ -0,0 +1,7 @@
+using Raylib;
+using static Raylib.Raylib;
+
+public partial class Examples
+{
+    /*******************************************************************************************
    *
    *   raylib [textures] example - Texture source and destination rectangles
    *
    *   This example has been created using raylib 1.3 (www.raylib.com)
    *   raylib is licensed under an unmodified zlib/libpng license (View raylib.h for details)
    *
    *   Copyright (c) 2015 Ramon Santamaria (@raysan5)
    *
    ********************************************************************************************/
    
    
    public static void Main()
    {
        // Initialization
        //--------------------------------------------------------------------------------------
        int screenWidth = 800;
        int screenHeight = 450;
    
        InitWindow(screenWidth, screenHeight, "raylib [textures] examples - texture source and destination rectangles");
    
        // NOTE: Textures MUST be loaded after Window initialization (OpenGL context is required)
        Texture2D scarfy = LoadTexture("resources/scarfy.png");        // Texture loading
    
        int frameWidth = scarfy.width/6;
        int frameHeight = scarfy.height;
        
        // NOTE: Source rectangle (part of the texture to use for drawing)
        Rectangle sourceRec = { 0, 0, frameWidth, frameHeight };
    
        // NOTE: Destination rectangle (screen rectangle where drawing part of texture)
        Rectangle destRec = { screenWidth/2, screenHeight/2, frameWidth*2, frameHeight*2 };
    
        // NOTE: Origin of the texture (rotation/scale point), it's relative to destination rectangle size
        Vector2 origin = { frameWidth, frameHeight };
        
        int rotation = 0;
        
        SetTargetFPS(60);
        //--------------------------------------------------------------------------------------
    
        // Main game loop
        while (!WindowShouldClose())    // Detect window close button or ESC key
        {
            // Update
            //----------------------------------------------------------------------------------
            rotation++;
            //----------------------------------------------------------------------------------
    
            // Draw
            //----------------------------------------------------------------------------------
            BeginDrawing();
    
                ClearBackground(RAYWHITE);
    
                // NOTE: Using DrawTexturePro() we can easily rotate and scale the part of the texture we draw
                // sourceRec defines the part of the texture we use for drawing
                // destRec defines the rectangle where our texture part will fit (scaling it to fit)
                // origin defines the point of the texture used as reference for rotation and scaling
                // rotation defines the texture rotation (using origin as rotation point)
                DrawTexturePro(scarfy, sourceRec, destRec, origin, rotation, WHITE);
    
                DrawLine(destRec.x, 0, destRec.x, screenHeight, GRAY);
                DrawLine(0, destRec.y, screenWidth, destRec.y, GRAY);
                
                DrawText("(c) Scarfy sprite by Eiden Marsal", screenWidth - 200, screenHeight - 20, 10, GRAY);
    
            EndDrawing();
            //----------------------------------------------------------------------------------
        }
    
        // De-Initialization
        //--------------------------------------------------------------------------------------
        UnloadTexture(scarfy);        // Texture unloading
    
        CloseWindow();                // Close window and OpenGL context
        //--------------------------------------------------------------------------------------
    
        return 0;
    }    
+}