Docs: Use let instead of const.

docs/index.html

@@ -445,7 +445,7 @@
 				// ['Geometry', '.morphTarget'] or ['Geometry', '#morphTarget']
 				// Note: According RFC 3986 no '#' allowed inside of an URL fragment!
 
-				const parts = [];
+				let parts = [];
 
 				const dotIndex = pageName.indexOf( oldDelimiter );