[Task]: Document results of actions

[hansva]

What needs to happen?

Migration: https://issues.apache.org/jira/browse/HOP-3357

Actions in a workflow have results which have result rows, result files, metrics and so on.

It's best to document these and how they can be accessed.

Issue Priority

Priority: 3

Issue Component

Component: Actions, Component: Documentation

[Adalennis]

.take-issue