Simplify JRE requirements description for better readability. (#4798)

* Simplify JRE requir for better readability.

#3474

* Update content/doc/administration/requirements/java.adoc

Co-authored-by: Tim Jacomb <21194782+timja@users.noreply.github.com>

* Update content/doc/administration/requirements/java.adoc

Co-authored-by: Tim Jacomb <21194782+timja@users.noreply.github.com>

* Update content/doc/administration/requirements/java.adoc

Co-authored-by: Tim Jacomb <21194782+timja@users.noreply.github.com>

Co-authored-by: Tim Jacomb <21194782+timja@users.noreply.github.com>

content/doc/administration/requirements/java.adoc

@@ -7,16 +7,13 @@ There are separate run and job execution requirements for Jenkins installations.
 
 ## Running Jenkins
 
-Modern Jenkins versions have the following Java requirements:
-
-* Java 8 runtime environments are supported in both 32-bit and 64-bit versions
-* Java 11 runtime environments are supported
-** Java 11 Docker installation instructions are included in link:/doc/book/installing/docker/#downloading-and-running-jenkins-in-docker["Downloading and running Jenkins in Docker"]
-** See the link:/doc/administration/requirements/upgrade-java-guidelines[Java 8 to Java 11 upgrade guidelines] for additional upgrade instructions
-* Java 7 and prior are not supported
-* Java 9 and 10 are not supported
-* Java 12, 13, 14, 15, and 16 are not supported
-* Java 17 is available for early adopters when using the Docker images (`jenkins/jenkins:jdk17-preview`)
+Java 8 or Java 11 are required for running modern versions of Jenkins. Upgrading an existing Jenkins setup from Java 8 to Java 11? See the link:/doc/administration/requirements/upgrade-java-guidelines[upgrade guidelines].
+
+Java 11 Docker installation instructions are included in link:/doc/book/installing/docker/#downloading-and-running-jenkins-in-docker["Downloading and running Jenkins in Docker"]
+
+Early adopters may use Java 17 as provided in the `jenkins/jenkins:jdk17-preview` Docker image.
+
+All other Java versions are not supported.
 
 These requirements apply to all components of the Jenkins system, including Jenkins controller,
 all types of agents, CLI clients, and other components.