This URL is only used because it is easy to remember.
Paralegal's documentation is actually hosted at https://justus-adam.notion.site/Paralegal-User-Guide-6e483e6ad03d4701bea245caf1345fcf?pvs=4 and you are being redirected there now.
Should the redirect fail you can also click the link.