Simplify multi instance configuration

[nikku]

Problem you would like to solve

As a user I want to understand quickly how multi-instance configuration works in the modeler. At the moment it is not 100% straight forward to bring together the UI and the documentation.

Editing UI in the Desktop Modeler.

Especially as the modeler links to the documentation I'd expect the documentation and modeler to work hand in hand.

Proposed solution

As a user, be able to clearly connect documentation and editing UI.

Alternatives considered

One way to improve the configuration is adding screenshots to the documentation.

Another way is to provide opinionated defaults to certain fields and/or feature them in both modeling UI and documentation, i.e. using software developer lingo:

for_each <inputElement> in <inputCollection>:
  <outputCollection>.append(<outputElement>)
  if <completionCondition>:
    break

Another way is to consider placeholders (inputElement, inputCollection) in the modeler UI to indicate use. We'd need to ensure that placeholders are not regarded as defaults in this case, which they are not.

Additional context

Brought up in https://camunda.slack.com/archives/C026U8GBNSW/p1682689014868189.