setup: renamed shader files for automatic syntax highlighting

fsq.glsl

@@ -0,0 +1,13 @@
+R"###(  
+#version 330 core
+layout (location = 0) in vec2 aPos;
+layout (location = 1) in vec2 aTexCoords;
+
+out vec2 texCoords;
+
+void main()
+{
+    texCoords = aTexCoords;
+    gl_Position = vec4(aPos.x, aPos.y, 0.0, 1.0); 
+}  
+)###";