Spring Cloud Commons Bootstrap is not enabled by default for Spring-Cloud-2022.0

Describe the bug
Really I'm just suggesting changes to breaking changes list, and to add spring-cloud-bootstrap-starter to spring-cloud-commons documentation so people can more easily make upgrades or get started with using Bootstrap configurations. Specifically:

spring.config.use-legacy-processing=true no longer enables bootstrap because of changes in Spring Boot 3.0. Please use spring.cloud.bootstrap.enabled=true.

Does not adequately describe the side-effects of the changeset here

Source: https://github.com/spring-cloud/spring-cloud-release/wiki/Spring-Cloud-2022.0-Release-Notes

Steps to reproduce:

• Use a spring cloud project prior to 2022, using a spring.factories class pointing to BootstrapConfiguration files. Do not use spring-cloud-starter-bootstrap
• Upgrade to 2022, following the migration guide

Expectations:

• Breaking changes list above describes that "spring.cloud.bootstrap.enabled does not default to true anymore." Users must.... [see Actual Behavior]"
• Add section that "spring-cloud-starter-bootstrap" will auto enabled bootstrap?

Actual behavior:

• BootstrapConfiguration does not load, until a system property is set as described above, or spring-cloud-bootstrap-starter is added which adds the Marker.java class that enabled BootstrapConfiguration initialization again.

Start with the Spring Cloud 2022.0 release notes wiki, the migration guide, and the linked spring-cloud-commons changeset. Update the breaking-changes explanation to cover the bootstrap behavior and document that adding spring-cloud-starter-bootstrap enables it; done means both upgrade guidance and starter usage are accurately described.