Added framebuffer to render screen to

core/Shaders/ScreenShader.cpp

@@ -0,0 +1,5 @@
+#include "ScreenShader.h"
+#include "screen.vert.h"
+#include "screen.frag.h"
+
+ScreenShader::ScreenShader() : Shader(screen_vert, screen_frag) {}

core/Shaders/ScreenShader.h

@@ -0,0 +1,6 @@
+#include "Shader.h"
+
+class ScreenShader : public Shader {
+public:
+  ScreenShader();
+};