I'm testing the new warning plugin (2.2.1) to prepare for migration our
pipelines and jobs to it. For this I've created thze following pipeline. To do
my first steps I used the examples given in the documentation:

https://github.com/jenkinsci/warnings-ng-plugin/blob/master/doc/Documentation.md#advanced-pipeline-configuration

 
There, for PMD reports, the following example is shown:

def pmd = scanForIssues tool: pmd(pattern: '**/target/pmd.xml')
{{ publishIssues issues: [pmd]}}

Trying to execute this ended in a NPE. After some hours of searching I found
that this is caused by the (still installed) "old" PMD-plugin (see
#JENKINS-55328). But until I found this JIRA-Ticket I found that in the
jenkins step documention there is no step "pmd" but a step called "pmdParser"
and using this worked.

https://jenkins.io/doc/pipeline/steps/warnings-ng/#scanforissues-scan-files-or-the-console-log-for-warnings-or-issues

So I suggest to update the documentation and correct this mistake / add a hint
as it is very misleading for beginners.