Structure transition labels

[codesoap]

Inspired by the discussion at #80 I have come up with a new suggestion for visualizing the different types of "self transitions". I'm using Graphviz ability to process HTML-like labels: https://graphviz.org/doc/info/shapes.html#html

The different types of transitions are now grouped and presented with a heading, which describes their type.

Exmaple

var (
	triggerEncounterProblem = "EncounterProblem"
	triggerPunchDesk        = "PunchDesk"
	triggerCry              = "Cry"
	triggerResolveProblems  = "ResolveProblems"
	stateHappy              = "Happy"
	stateUnhappy            = "Unhappy"
)
mood := stateless.NewStateMachine(stateHappy)
mood.Configure(stateHappy).
	Permit(triggerEncounterProblem, stateUnhappy)
mood.Configure(stateUnhappy).
	Permit(triggerResolveProblems, stateHappy).
	PermitReentry(triggerEncounterProblem).
	Ignore(triggerPunchDesk).
	Ignore(triggerCry)

Is rendered this way: