chore(README): improve readme
chore(README): improve readme

camunda/camunda-bpm-elasticsearch,nagyistoce/camunda-bpm-elasticsearch,camunda/camunda-bpm-elasticsearch,nagyistoce/camunda-bpm-elasticsearch,nagyistoce/camunda-bpm-elasticsearch,camunda/camunda-bpm-elasticsearch,camunda/camunda-bpm-elasticsearch,nagyistoce/camunda-bpm-elasticsearch