Fixing xref I created incorrectly

Author: hackermatthew

ch01.asciidoc

@@ -328,7 +328,7 @@ ES6 is big: the language specification went from 258 pages in ES5.1 to over doub
 - More built-ins and methods
 - Non-breaking solutions to existing limitations
 
-Syntactic sugar is one of the most significant drivers in ES6. The new version offers a shorter ways of expressing object inheritance, using the new class syntax; functions, using a shorthand syntax known as arrow functions; and properties, using property value shorthands. Several other features we'll explore, such as destructuring, rest and spread, also offer semantically sound ways of writing programs. Chapters pass:[<a data-type="xref" data-xrefstyle="select:labelnumber" href="#ecmascript6">#ecmascript6</a>] and pass:[<a data-type="xref" data-xrefstyle="select:labelnumber" href="#classes-symbols-and-symbols">#classes-symbols-and-symbols</a>] attack these aspects of ES6.
+Syntactic sugar is one of the most significant drivers in ES6. The new version offers a shorter ways of expressing object inheritance, using the new class syntax; functions, using a shorthand syntax known as arrow functions; and properties, using property value shorthands. Several other features we'll explore, such as destructuring, rest and spread, also offer semantically sound ways of writing programs. Chapters pass:[<a data-type="xref" data-xrefstyle="select:labelnumber" href="#ecmascript6-essentials">#ecmascript6-essentials</a>] and pass:[<a data-type="xref" data-xrefstyle="select:labelnumber" href="#classes-symbols-and-symbols">#classes-symbols-and-symbols</a>] attack these aspects of ES6.
 
 We get several new mechanics to describe asynchronous code flows in ES6: promises, which represent the eventual result of an operation; iterators, which represent a sequence of values; and generators, a special kind of iterator which can produce a sequence of values. In ES2017, `async`/`await` builds on top of these new concepts and constructs, letting us write asynchronous routines that appear synchronous. We'll evaluate all of these iteration and flow control mechanisms in <<iteration-and-flow-control>>.