Spring Security Improve deprecation notice in WebSecurityConfigurerAdapter

The WebSecurityConfigurerAdapter has been deprecated and its javadoc is too hard to understand how to replace it.

We should be clearer on how to publish a SecurityFilterChain bean and WebSecurityCustomizer, and consider linking to the blog post https://spring.io/blog/2022/02/21/spring-security-without-the-websecurityconfigureradapter