Possible incosistency in chapter 5 documentation

In Chapter 5. Schema and Data Modeling first there is paragraph:

> The default cardinality setting is SINGLE. Note, that property keys used on edges and properties have cardinality SINGLE. Attaching multiple values for a single key on an edge or property is not supported.

and then example:

```
mgmt = graph.openManagement()
follow = mgmt.makeEdgeLabel('follow').multiplicity(MULTI).make()
name = mgmt.makePropertyKey('name').dataType(String.class).cardinality(Cardinality.SET).make()
mgmt.addProperties(follow, name)
mgmt.commit()
```

doesn't this example contradict that edges can't have multiple values for a single key?

Start with Chapter 5, “Schema and Data Modeling,” and compare the paragraph about SINGLE cardinality with the shown edge-label and property-key example. Determine whether the example contradicts the explanation, then clarify the documentation so the supported cardinality behavior is unambiguous.

Written by the indexing model from the issue text.