Update necessary word for vocabulary checking

docs/api/en/renderers/WebGLRenderer.html

@@ -253,7 +253,7 @@
 
 		Note: Sorting is used to attempt to properly render objects that have some degree of transparency.
 		By definition, sorting objects may not work in all cases.  Depending on the needs of application,
-		it may be neccessary to turn off sorting and use other methods to deal with transparency
+		it may be necessary to turn off sorting and use other methods to deal with transparency
 		rendering e.g. manually determining each object's rendering order.
 		</p>