Spring Experiment with aggregateJavadoc task in Spring Javadoc plugin

Experiment with the aggregateJavadoc Gradle task by @rwinch and provide feedback.

Comment From: rwinch

Here is what I have using the snapshots https://github.com/rwinch/spring-framework/tree/gh-24653-aggregatejavadoc

Comment From: rwinch

I have released 0.0.1 version and created a PR that will close this issue https://github.com/spring-projects/spring-framework/pull/24715

Comment From: sbrannen

Thanks, @rwinch! I've slated your PR for 5.2.5.