[TINKERPOP-2491] Fix docs by adding missing unfolds (#3250)

https://issues.apache.org/jira/browse/TINKERPOP-2491

Fix documentation build by adding missing unfold() which are required after TINKERPOP-2491 was merged.

Author: andreachild

docs/src/recipes/appendix.asciidoc

@@ -311,7 +311,7 @@ g.addV('person').property('name','alice').as('alice').
       times(3).emit().
     select(all, "x").
     project("name","score").
-      by(tail(local, 1).select("a").values("name")).
+      by(tail(local, 1).unfold().select("a").values("name")).
       by(unfold().
          sack(assign).by(select("b")).
          sack(mult).by(select("c")).

docs/src/recipes/recommendation.asciidoc

@@ -199,7 +199,7 @@ g.V().has("person","name","alice").as("alice").
       where(within("self")).count()).as("g").
       select(values).
       order(local).
-        by(desc).limit(local, 1).as("m").
+        by(desc).limit(local, 1).unfold().as("m").
       select("g").unfold().
       where(select(values).as("m")).select(keys)
 ----
@@ -217,7 +217,7 @@ g.V().has("person","name","alice").as("alice").
       where(within("self")).count()).as("g").
       select(values).
       order(local).
-        by(desc).limit(local, 1).as("m").
+        by(desc).limit(local, 1).unfold().as("m").
       select("g").unfold().
       where(select(values).as("m")).select(keys).
       out("bought").where(without("self"))
@@ -235,7 +235,7 @@ g.V().has("person","name","alice").as("alice").
       where(within("self")).count()).as("g").
       select(values).
       order(local).
-        by(desc).limit(local, 1).as("m").
+        by(desc).limit(local, 1).unfold().as("m").
       select("g").unfold().
       where(select(values).as("m")).select(keys).
       out("bought").where(without("self")).

docs/src/recipes/shortest-path.asciidoc

@@ -187,7 +187,7 @@ g.withSideEffect('v', []).                            <1>
   unfold().
   map(unfold().as('v_or_e').
       coalesce(V().where(eq('v_or_e')).aggregate(local,'v'),
-               select('v').tail(local, 1).bothE().where(eq('v_or_e'))).
+               select('v').tail(local, 1).unfold().bothE().where(eq('v_or_e'))).
       values('name','weight').
       fold()).
   group().

docs/src/reference/the-traversal.asciidoc

@@ -3311,13 +3311,13 @@ contains additional information that will be applied if an existing vertex is fo
 ----
 g.inject([[(T.id):400],[(T.label):'Dog',name:'Pixel',age:1],[updated:'2022-02-1']]).as('m').
   mergeV(select('m').limit(local,1).unfold()). <1>
-  option(Merge.onCreate, select('m').range(local,1,2)). <2>
-  option(Merge.onMatch, select('m').tail(local)) <3>
+  option(Merge.onCreate, select('m').range(local,1,2).unfold()). <2>
+  option(Merge.onMatch, select('m').tail(local).unfold()) <3>
 g.V(400).valueMap().with(WithOptions.tokens)
 g.inject([[(T.id):400],[(T.label):'Dog',name:'Pixel',age:1],[updated:'2022-02-1']]).as('m').
   mergeV(select('m').limit(local,1).unfold()).
-  option(Merge.onCreate, select('m').range(local,1,2)).
-  option(Merge.onMatch, select('m').tail(local))  <4>
+  option(Merge.onCreate, select('m').range(local,1,2).unfold()).
+  option(Merge.onMatch, select('m').tail(local).unfold())  <4>
 g.V(400).valueMap().with(WithOptions.tokens)  <5>
 ----