[examples] Add new example: shaders_vertex_displacement (#4186)

* shaders-vertex_displacement init

* implement simulation of wave in ocean

* update examples/README & add some comments

* update comments

* add gl100 shaders

examples/shaders/resources/shaders/glsl330/vertex_displacement.fs

@@ -0,0 +1,16 @@
+#version 330
+
+// Input fragment attributes (from fragment shader)
+in vec2 fragTexCoord;
+in float height;
+
+// Output fragment color
+out vec4 finalColor;
+
+void main()
+{
+    vec4 darkblue = vec4(0.0, 0.13, 0.18, 1.0);
+    vec4 lightblue = vec4(1.0, 1.0, 1.0, 1.0);
+    // interplate between two colors based on height
+    finalColor = mix(darkblue, lightblue, height);
+}