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/core/core_random_values.cs

@@ -0,0 +1,7 @@
+using Raylib;
+using static Raylib.Raylib;
+
+public partial class Examples
+{
+    /*******************************************************************************************
    *
    *   raylib [core] example - Generate random values
    *
    *   This example has been created using raylib 1.1 (www.raylib.com)
    *   raylib is licensed under an unmodified zlib/libpng license (View raylib.h for details)
    *
    *   Copyright (c) 2014 Ramon Santamaria (@raysan5)
    *
    ********************************************************************************************/
    
    
    public static void Main()
    {
        // Initialization
        //--------------------------------------------------------------------------------------
        int screenWidth = 800;
        int screenHeight = 450;
    
        InitWindow(screenWidth, screenHeight, "raylib [core] example - generate random values");
    
        int framesCounter = 0;  // Variable used to count frames
    
        int randValue = GetRandomValue(-8, 5);   // Get a random integer number between -8 and 5 (both included)
    
        SetTargetFPS(60);       // Set our game to run at 60 frames-per-second
        //--------------------------------------------------------------------------------------
    
        // Main game loop
        while (!WindowShouldClose())    // Detect window close button or ESC key
        {
            // Update
            //----------------------------------------------------------------------------------
            framesCounter++;
    
            // Every two seconds (120 frames) a new random value is generated
            if (((framesCounter/120)%2) == 1)
            {
                randValue = GetRandomValue(-8, 5);
                framesCounter = 0;
            }
            //----------------------------------------------------------------------------------
    
            // Draw
            //----------------------------------------------------------------------------------
            BeginDrawing();
    
                ClearBackground(RAYWHITE);
    
                DrawText("Every 2 seconds a new random value is generated:", 130, 100, 20, MAROON);
    
                DrawText(FormatText("%i", randValue), 360, 180, 80, LIGHTGRAY);
    
            EndDrawing();
            //----------------------------------------------------------------------------------
        }
    
        // De-Initialization
        //--------------------------------------------------------------------------------------
        CloseWindow();        // Close window and OpenGL context
        //--------------------------------------------------------------------------------------
    
        return 0;
    }    
+}