zh doc: a little spelling fix

docs/examples/zh/loaders/MTLLoader.html

@@ -12,7 +12,7 @@
 
 		<h1>[name]</h1>
 
-		<p class="desc">A loader for loading an <em>.mtl</em> resource, used internaly by [page:OBJLoader].<br />
+		<p class="desc">A loader for loading an <em>.mtl</em> resource, used internally by [page:OBJLoader].<br />
 		The Material Template Library format (MTL) or .MTL File Format is a companion file format to .OBJ that describes surface shading
 		(material) properties of objects within one or more .OBJ files.
 		</p>