Added new vertex shader file naturalA.vsh

This fixes the trembling issue

assets/shaders/naturalA.vsh

@@ -0,0 +1,12 @@
+uniform vec2 u_texelDelta;
+
+attribute vec4 a_position;
+attribute vec2 a_texcoord0;
+
+varying vec2 v_texcoord0;
+
+void main()
+{
+  gl_Position=a_position;
+  v_texcoord0=a_texcoord0;
+}