Update documentation following changes to executable jar layout

See gh-4897

spring-boot-docs/src/main/asciidoc/appendix-executable-jar-format.adoc

@@ -42,16 +42,18 @@ Spring Boot Loader compatible jar files should be structured in the following wa
 	 |     +-boot
 	 |        +-loader
 	 |           +-<spring boot loader classes>
-	 +-com
+	 +-BOOT-INF
+	    +-classes
 	    |  +-mycompany
-	 |     + project
+	    |     +-project
 	    |        +-YouClasses.class
 	    +-lib
 	       +-dependency1.jar
 	       +-dependency2.jar
 ----
 
-Dependencies should be placed in a nested `lib` directory.
+Application classes should be placed in a nested `BOOT-INF/classes` directory.
+Dependencies should be placed in a nested `BOOT-INF/lib` directory.