Polishing.

See spring-projects#2247

Author: sothawo

README.adoc

@@ -1,4 +1,3 @@
-
 image:https://spring.io/badges/spring-data-elasticsearch/ga.svg[Spring Data Elasticsearch,link=https://projects.spring.io/spring-data-elasticsearch#quick-start] image:https://spring.io/badges/spring-data-elasticsearch/snapshot.svg[Spring Data Elasticsearch,link=https://projects.spring.io/spring-data-elasticsearch#quick-start]
 
 = Spring Data for Elasticsearch image:https://jenkins.spring.io/buildStatus/icon?job=spring-data-elasticsearch%2Fmain&subject=Build[link=https://jenkins.spring.io/view/SpringData/job/spring-data-elasticsearch/] https://gitter.im/spring-projects/spring-data[image:https://badges.gitter.im/spring-projects/spring-data.svg[Gitter]]
@@ -191,7 +190,9 @@ Attach a link to your code or a compressed file containing your code.
 == Building from Source
 
 You don’t need to build from source to use Spring Data (binaries in https://repo.spring.io[repo.spring.io]), but if you want to try out the latest and greatest, Spring Data can be easily built with the https://github.com/takari/maven-wrapper[maven wrapper].
-You also need JDK 17 or above.
+
+You need JDK 17 or above to build the _main_ branch.
+For the branches up to and including release 4.4, JDK 8 is required.
 
 [source,bash]
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@@ -205,7 +206,6 @@ _Also see link:CONTRIBUTING.adoc[CONTRIBUTING.adoc] if you wish to submit pull r
 IMPORTANT: When contributing, please make sure an issue exists in https://github.com/spring-projects/spring-data-elasticsearch/issues[issue tracker] and comment on this issue with how you want to address it.
 By this we not only know that someone is working on an issue, we can also align architectural questions and possible solutions before work is invested . We so can prevent that much work is put into Pull Requests that have little or no chances of being merged.
 
-
 === Building reference documentation
 
 Building the documentation builds also the project without running tests.