httpRef and functionRef in pre-defined containers can not run multiple executables

[StackScribe]

The published KeptnTaskDefinition reference page and Executing sequential tasks guide material imply that the httpRef and functionRef syntax of the pre-defined containers can be used to call multiple executables within one KeptnTaskDefinition resource.

In fact, each of these can call a maximum of two webserver scripts (for httpRef) or two KeptnTaskDefinition resources (for functionRef), one of which calls executable code and the other of which defines parameters to pass to that executable code. To create a KeptnTaskDefinition that runs a sequence of executables, you must either use the inline syntax in a pre-defined container or, for the most flexibility, create a Kubernetes container that runs in a Keptn custom-runtime runner.

h/t @RealAnna