Dataset JSON is incorrect
## Describe the bug

The JSON file generated for https://github.com/huggingface/datasets/blob/573f3d35081cee239d1b962878206e9abe6cde91/datasets/journalists_questions/journalists_questions.py is https://github.com/huggingface/datasets/blob/573f3d35081cee239d1b962878206e9abe6cde91/datasets/journalists_questions/dataset_infos.json.

The only config should be `plain_text`, but the first key in the JSON is `journalists_questions` (the dataset id) instead.

```json
{
  "journalists_questions": {
    "description": "The journalists_questions corpus (version 1.0) is a collection of 10K human-written Arabic\ntweets manually labeled for question identification over Arabic tweets posted by journalists.\n",
    ...
```

## Steps to reproduce the bug

Look at the files.

## Expected results

The first key should be `plain_text`:

```json
{
  "plain_text": {
    "description": "The journalists_questions corpus (version 1.0) is a collection of 10K human-written Arabic\ntweets manually labeled for question identification over Arabic tweets posted by journalists.\n",
    ...
```

## Actual results

```json
{
  "journalists_questions": {
    "description": "The journalists_questions corpus (version 1.0) is a collection of 10K human-written Arabic\ntweets manually labeled for question identification over Arabic tweets posted by journalists.\n",
    ...
```

