feat(method-reference): arquivos e referências

Acrescentado arquivos e referências iniciais para a seção de Method Reference.

Issue #22

Author: rinaldodev

book/04-lambda/sections/04-method-reference.asc

@@ -0,0 +1,24 @@
+:java-package: src/org/j6toj8/lambda
+:section-java-package: ../../../{java-package}
+
+=== Referências a Métodos (Method Reference)
+
+.Objetivo
+--------------------------------------------------
+Develop code that uses a method reference, including refactoring a lambda expression to a method reference.
+-
+Desenvolver código que utiliza uma referência a método, incluindo a refatoração de uma expressão lambda para uma referência a método.
+--------------------------------------------------
+
+.Referências
+****
+
+* Using Method References
++
+Boyarsky, Jeanne; Selikoff, Scott. OCP: Oracle Certified Professional Java SE 8 Programmer II Study Guide (p. 152). Wiley. Edição do Kindle. 
+
+* https://www.baeldung.com/java-method-references[Method References in Java.]
+
+* https://docs.oracle.com/javase/tutorial/java/javaOO/methodreferences.html[Method References.] The Java™ Tutorials.
+
+****

ch04-lambda.asc

@@ -3,4 +3,5 @@
 
 include::book/04-lambda/sections/01-functional-interfaces.asc[]
 include::book/04-lambda/sections/02-lambda-expression.asc[]
-include::book/04-lambda/sections/03-built-in-interfaces.asc[]
+include::book/04-lambda/sections/03-built-in-interfaces.asc[]
+include::book/04-lambda/sections/04-method-reference.asc[]