gatsby-node.js
async function moveIndex(client, sourceIndex, targetIndex) {
  const { taskID } = await client.moveIndex(
    sourceIndex.indexName,
    targetIndex.indexName
  );
  return targetIndex.waitTask(taskID);
}
async function moveIndex(client, sourceIndex, targetIndex) {
  const { taskID } = await client.moveIndex(
    sourceIndex.indexName,
    targetIndex.indexName
  );
  return targetIndex.waitTask(taskID);
}
moves the source index to the target index
@param client
@param sourceIndex
@param targetIndex
@return {Promise}