Box3.html: Correct typo

docs/api/math/Box3.html

@@ -103,7 +103,7 @@
 
 		<h3>[method:Box3 setFromBufferAttribute]( [page:BufferAttribute attribute] ) [page:Box3 this]</h3>
 		<div>
-		buffer -- An buffer attribute of position data that the resulting box will envelop.
+		buffer -- A buffer attribute of position data that the resulting box will envelop.
 		</div>
 		<div>
 		Sets the upper and lower bounds of this box to include all of the data in *attribute*.