Update WebGLRenderer docs (build in -> built in)

As stated in title, "build in" appears to be a mistake and should be "built in"

docs/api/en/renderers/WebGLRenderer.html

@@ -425,7 +425,7 @@
 
 		<h3>[method:null setAnimationLoop]( [param:Function callback] )</h3>
 		<p>[page:Function callback] — The function will be called every available frame. If `null` is passed it will stop any already ongoing animation.</p>
-		<p>A build in function that can be used instead of [link:https://developer.mozilla.org/en-US/docs/Web/API/window/requestAnimationFrame requestAnimationFrame]. For WebVR projects this function must be used.</p>
+		<p>A built in function that can be used instead of [link:https://developer.mozilla.org/en-US/docs/Web/API/window/requestAnimationFrame requestAnimationFrame]. For WebVR projects this function must be used.</p>
 
 		<h3>[method:null setClearAlpha]( [param:Float alpha] )</h3>
 		<p>Sets the clear alpha. Valid input is a float between *0.0* and *1.0*.</p>