example/service/dynamodb: Update example documentation
Updates the example documentation to include missing information on tags and options.
Fixup of
@@ -13,6 +13,7 @@ type Item struct {
Data map[string]interface{}
}
```
+Use Go tags to define what the name is of the attribute in your DynamoDB table. See [AWS SDK for Go API Reference: Marshal](http://docs.aws.amazon.com/sdk-for-go/api/service/dynamodb/dynamodbattribute/#Marshal) for more information.
In DynamoDB the structure of the item to be returned will be:
```json
