Add JFR plugin

Author: joshiraezcode

modules/ROOT/pages/plugins.adoc

@@ -27,9 +27,8 @@ a|Allows you to connect to local or remote JVMs.
 
 Requirements:: The Discover tab requires `io.hawt:hawtio-local-jvm-mbean` to the dependencies.
 
-|Diagnostics
-|Allows you to control the Java Flight Recorder, see class histogram and access to JVM flags. +
-*Not yet ported to v3.*
+|https://github.com/hawtio/hawtio-next/tree/main/packages/hawtio/src/plugins/diagnostics[Diagnostics]
+|The Diagnostics plugin allows you to retrieve information from your Java runtime. Implements the Java Flight Recorder.
 
 |https://github.com/hawtio/hawtio-next/tree/main/packages/hawtio/src/plugins/jmx[JMX]
 |Provides the core https://www.oracle.com/java/technologies/javase/javamanagement.html[JMX] support for interacting with MBeans, viewing real time attributes, charting, and invoking operations.