In Ubuntu, if a user types in a command that isn't yet installed, you get names of packages that you can install to bring that command:
Jenkins does this kind of things too elsewhere, for example in the form validation — where we expect people to type in a job name, if the specified name doesn't exist, not only do we tell them so but we look for nearest job name and suggest that as "perhaps you meant xyz?".
Pipeline plugin should do this, too. We now have the list of known pipeline extensions and what steps and variables they bring to the system, so we can do the approximation of this.
Attention like this makes a big difference in the impression of pipeline to new users, as everyone makes mistakes and how quickly we can get them unstuck is a critical part of the user experience.