SpringBoot Updated documentation for @ConfigurationProperties bean naming rules

Added sample class with a prefix to clarify bean naming rules and fixed the corresponding documentation. Fixes #33437

Comment From: wilkinsona

Note for when we merge: SomeProperties does not need to be made public and can remain package-private.

Edit: Scratch that, the class becoming public makes it more consistent with other examples in the docs

Comment From: wilkinsona

@Anubhav-2000 Thanks very much for making your first contribution to Spring Boot.