문서 삭제

DELETE [인덱스_이름]/_doc/[_id값]

DELETE my_index/_doc/1

## 결과
{
  "_index": "my_index",
  "_id": "1",
  "_version": 4,
  "result": "deleted",
  "_shards": {
    "total": 2,
    "successful": 1,
    "failed": 0
  },
  "_seq_no": 4,
  "_primary_term": 1
}