Add example of improved option() capability.

[krlawrence]

Release 3.4.3 added the ability for option steps used with a choose step to include traversals so constructs like the one below are now possible.

g.V().hasLabel('airport').
      groupCount().
        by(__.choose(__.values('elev')).
                     option(gt(5000),__.constant('high')).
                     option(gt(3000),__.constant('medium')).
                     option(Pick.none,__.constant('low'))) 

Also show to do it before would have taken something like

res = ( g.V().hasLabel('airport').
              groupCount().
                by(__.choose(__.values('elev').is_(gt(5000)),
                             __.constant('high'),
                             __.choose(__.values('elev').is_(gt(3000)),
                                       __.constant('medium'),
                                       __.constant('low')))).
              order(Scope.local).by(Column.values).
              next() )

As part of this also document the Pick enum.
org.apache.tinkerpop.gremlin.process.traversal.step.TraversalOptionParent.Pick

Maybe also show something like this as the old option usage

gremlin> g.V().hasLabel('airport').
......1>       has('region','US-TX').fold().
......2>       choose(count(local)).
......3>         option(1,constant('one')).
......4>         option(0,constant('none')).
......5>         option(none,constant('neither one or zero'))
==>neither one or zero
gremlin> g.V().hasLabel('airport').
......1>       has('code','AUS').fold().
......2>       choose(count(local)).
......3>         option(1,constant('one')).
......4>         option(0,constant('none')).
......5>         option(none,constant('neither one or zero'))
==>one
gremlin> g.V().hasLabel('airport').
......1>       has('code','XYZ').fold().
......2>       choose(count(local)).
......3>         option(1,constant('one')).
......4>         option(0,constant('none')).
......5>         option(none,constant('neither one or zero'))
==>none       

As part of this update the Pick enum needs to be added to the list of enum tables

[krlawrence]

Closing as this is fixed and work has now started on the second edition. There will likely be one final release of the v283 first edition line before the V2 branch becomes the second edition. That release will include these fixes.