Restore projects/CMake/CMakeLists.txt (#5191)

For some reason, #5181 deleted it.
This project is intended to be a simple template to set up a project
consuming raylib with CMake.

projects/CMake/core_basic_window.c

@@ -0,0 +1,83 @@
+/*******************************************************************************************
+*
+*   raylib [core] example - Basic window (adapted for HTML5 platform)
+*
+*   This example is prepared to compile for PLATFORM_WEB and PLATFORM_DESKTOP
+*   As you will notice, code structure is slightly different to the other examples...
+*   To compile it for PLATFORM_WEB just uncomment #define PLATFORM_WEB at beginning
+*
+*   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)
+*
+********************************************************************************************/
+
+#include "raylib.h"
+
+#if defined(PLATFORM_WEB)
+    #include <emscripten/emscripten.h>
+#endif
+
+//----------------------------------------------------------------------------------
+// Global Variables Definition
+//----------------------------------------------------------------------------------
+int screenWidth = 800;
+int screenHeight = 450;
+
+//----------------------------------------------------------------------------------
+// Module Functions Declaration
+//----------------------------------------------------------------------------------
+void UpdateDrawFrame(void);     // Update and Draw one frame
+
+//----------------------------------------------------------------------------------
+// Program main entry point
+//----------------------------------------------------------------------------------
+int main()
+{
+    // Initialization
+    //--------------------------------------------------------------------------------------
+    InitWindow(screenWidth, screenHeight, "raylib [core] example - basic window");
+
+#if defined(PLATFORM_WEB)
+    emscripten_set_main_loop(UpdateDrawFrame, 0, 1);
+#else
+    SetTargetFPS(60);   // Set our game to run at 60 frames-per-second
+    //--------------------------------------------------------------------------------------
+
+    // Main game loop
+    while (!WindowShouldClose())    // Detect window close button or ESC key
+    {
+        UpdateDrawFrame();
+    }
+#endif
+
+    // De-Initialization
+    //--------------------------------------------------------------------------------------
+    CloseWindow();        // Close window and OpenGL context
+    //--------------------------------------------------------------------------------------
+
+    return 0;
+}
+
+//----------------------------------------------------------------------------------
+// Module Functions Definition
+//----------------------------------------------------------------------------------
+void UpdateDrawFrame(void)
+{
+    // Update
+    //----------------------------------------------------------------------------------
+    // TODO: Update your variables here
+    //----------------------------------------------------------------------------------
+
+    // Draw
+    //----------------------------------------------------------------------------------
+    BeginDrawing();
+
+        ClearBackground(RAYWHITE);
+
+        DrawText("Congrats! You created your first window!", 190, 200, 20, LIGHTGRAY);
+
+    EndDrawing();
+    //----------------------------------------------------------------------------------
+}