Migrate 'Parameterized System Groovy script' page from wiki

[getJv]

Essential information

• Page to Migrate: https://wiki.jenkins.io/display/JENKINS/Parameterized+System+Groovy+script#
• (Proposal) New section under destination: https://www.jenkins.io/doc/book/managing/groovy-hook-scripts/

Watch the tutorial to learn more about each page migration process:

Additional information

Note: check jenkins.io first to see if there's content for this already, possibly there's some useful content on the wiki that should be pulled in

This is one of the top most visited page on the wiki according to:
https://wiki.jenkins.io/.well-known/reports/top_urls.txt

It should be improved on and cleaned up, not just imported,

You can use the wiki-exporter to save some time:
https://jenkins-wiki-exporter.jenkins.io/

Redirecting pages

After it has been migrated a redirect should be setup, by sending a PR to this file:
https://github.com/jenkins-infra/jenkins-infra/blob/staging/dist/profile/templates/confluence/vhost.conf,
see past PRs for examples, or just take a look.