Added some simple test text.

assets/shaders/glsl/ui.vert

@@ -0,0 +1,24 @@
+#version 460
+
+layout(set = 1, binding = 0)
+uniform Parameters
+{
+    vec2 u_windowSize;
+};
+
+layout(location = 0)
+in vec2 i_position;
+
+layout(location = 1)
+in vec2 i_texCoord;
+
+layout(location = 0)
+out vec2 o_texCoord;
+
+void main()
+{
+    vec2 relativePos = 2.0 * (i_position / u_windowSize) - vec2(1.0);
+    relativePos.y *= -1.0;
+    gl_Position = vec4(relativePos, 0.0, 1.0);
+    o_texCoord = i_texCoord;
+}