Provide more explict instructions regarding the necessary import
to make the Kotlin DSL work. For some reason it took me 10 minutes
to figure this out based on the existing doc.
Before, Spring Security's @Enable* annotations were meta-annotated with @Configuration.
While convenient, this is not consistent with the rest of the Spring projects and most notably
Spring Framework's @Enable annotations. Additionally, the introduction of support for
@Configuration(proxyBeanMethods=false) in Spring Framework provides a compelling reason to
remove @Configuration meta-annotation from Spring Security's @Enable annotations and allow
users to opt into their preferred configuration mode.
Closes gh-6613
Signed-off-by: Joshua Sattler <joshua.sattler@mailbox.org>