quickstart field in datagen connector

[chainhead]

Is the quickstart field mandatory?

This configuration does not work.

{
  "name": "rawdatagen",
  "connector.class": "io.confluent.kafka.connect.datagen.DatagenConnector",
  "key.converter": "org.apache.kafka.connect.storage.StringConverter",
  "kafka.topic": "pageviews",
  "max.interval": "100",
  "iterations": "1000000"
}

But, this one works.

{
  "name": "rawdatagen",
  "connector.class": "io.confluent.kafka.connect.datagen.DatagenConnector",
  "key.converter": "org.apache.kafka.connect.storage.StringConverter",
  "kafka.topic": "pageviews",
  "max.interval": "100",
  "iterations": "1000000",
  "quickstart": "pageviews"
}

Also, I am using the Docker version as described here. So, if I wanted to add my own quickstart, do I have to rebuild this Dockerfile and use the same when bringing up Kafka?