update readme

Author: mattneub

README.md

@@ -1,7 +1,7 @@
 
 These are the **complete downloadable code examples** for my upcoming books, _iOS 9 Programming Fundamentals With Swift_ (<http://shop.oreilly.com/product/0636920044345.do>) and _Programming iOS 9_ (<http://shop.oreilly.com/product/0636920044352.do>).
 
-Examples have been revised for Swift 2.0 and Xcode 7. At the time of this writing, the examples are complete for the first book; for the second book, we're done up through chapter 22. Please keep in mind that subsequent chapters of the second book have _not yet been revised_.
+Examples have been revised for Swift 2.0 and Xcode 7. At the time of this writing, the examples are complete for the first book; for the second book, we're done up through chapter 23. Please keep in mind that subsequent chapters of the second book have _not yet been revised_.
 
 If you find these examples helpful and you haven't purchased the books, please consider doing so.