Fix escaping

Author: snicoll

README.adoc

@@ -80,7 +80,7 @@ requests. If you want to raise an issue, please follow the recommendations below
 * Please provide as much information as possible with the issue report, we like to know
   the version of Spring Boot that you are using, as well as your Operating System and
   JVM version.
-* If you need to paste code, or include a stack trace use Markdown ++$$```$$++ escapes
+* If you need to paste code, or include a stack trace use Markdown +++```+++ escapes
   before and after your text.
 * If possible try to create a test-case or project that replicates the issue. You can
   submit sample projects as pull-requests against the