Improve deprecation notice in WebSecurityConfigurerAdapter #12260
Description
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