[Documentation] Incorrect description on Activity Final Node and Flow Final Node in the User guide

[vhemery]

On the user guide, there is

Element	Representation	Comments
Activity Final Node		End of a flow
Flow Final Node		Exit from the system

I think the 2 descriptions were inverted... (at least that's how I understand them)

15.3.3.2 of UML spec tells us that ActivityFinalNode terminates the activity whereas FlowFinalNode only destroys a flow without impacting others.