add link to show all bom versions
This new parent POM is decoupled from the core Jenkins project, both from the Maven and repository perspectives.
-Since version 4.0 the plugin pom supports Jenkins 2.200 and higher and a select few older LTS lines (TBD)
+Since version 4.0 the plugin pom supports Jenkins 2.200 and higher and a select few older LTS lines ([full list](https://repo.jenkins-ci.org/releases/org/jenkins-ci/main/jenkins-bom/))
The main changes are:
* Reduced number of overridable properties. All references (e.g. dependencies and plugin versions) not
