Add Skybox Example (#5)

* added skybox example

* use existing resource directory

examples/models/resources/shaders/cubemap.vs

@@ -8,21 +8,21 @@
 
 #version 330
 
-# Input vertex attributes
-in vec3 vertexPosition
+// Input vertex attributes
+in vec3 vertexPosition;
 
-# Input uniform values
-uniform mat4 projection
-uniform mat4 view
+// Input uniform values
+uniform mat4 projection;
+uniform mat4 view;
 
-# Output vertex attributes (to fragment shader)
-out vec3 fragPos
+// Output vertex attributes (to fragment shader)
+out vec3 fragPosition;
 
 void main()
-[
-    # Calculate fragment position based on model transformations
-    fragPos = vertexPosition
+{
+    // Calculate fragment position based on model transformations
+    fragPosition = vertexPosition;
 
-    # Calculate final vertex position
-    gl_Position = projection*view*vec4(vertexPosition, 1.0)
-]
+    // Calculate final vertex position
+    gl_Position = projection*view*vec4(vertexPosition, 1.0);
+}