Remove unneeded jump_ahead parameter

README.adoc

 
 include::https://raw.github.com/spring-guides/getting-started-macros/master/prereq_editor_jdk_buildtools.adoc[]
 
-:jump_ahead: Learn what you can do with Spring Boot
 include::https://raw.github.com/spring-guides/getting-started-macros/master/how_to_complete_this_guide.adoc[]