Added shaders and textures for the main menu.

assets/shaders/bckg/bckg.vert

@@ -0,0 +1,11 @@
+uniform mat4 u_projTrans;
+
+attribute vec4 a_position;
+attribute vec2 a_texCoord0;
+
+varying vec2 v_texCoords;
+
+void main(){
+	v_texCoords = a_texCoord0;
+	gl_Position = u_projTrans * a_position;
+}