I'm considering the following array of JSON objects:

```
[
  {
    "index": "index1",
    "type": "type1",
    "id": "id1",
    "fields": {
      "deviceOs": [
        "Android"
      ],
      "deviceID": [
        "deviceID1"
      ],
      "type": [
        "type"
      ],
      "country": [
        "DE"
      ]
    }
  },
  {
    "index": "index2",
    "type": "type2",
    "id": "id2",
    "fields": {
      "deviceOs": [
        "Android"
      ],
      "deviceID": [
        "deviceID2"
      ],
      "type": [
        "type"
      ],
      "country": [
        "US"
      ]
    }
  }
]

```

and I would like to flatten it to get:

```
[
  {
    "index": "index1",
    "type": "type",
    "id": "id1",
    "deviceOs": "Android",
    "deviceID": "deviceID1",
    "country": "DE"
  },
  {
    "index": "index2",
    "type": "type",
    "id": "id2",
    "deviceOs": "Android",
    "deviceID": "deviceID2",
    "country": "US"
  }
]

```

I'm trying to work with `jq` but I fail to flatten the `"fields"`. How should I do it? At the moment I'm interested in command-line tools, but I'm open to other suggestions as well.