Metadata correction for 2020.lrec-1.531

### JSON data block

```json
{
"anthology_id": "2020.lrec-1.531",
"authors": [
{
"first": "Cleber de S.",
"last": "Alcântara",
"id": "cleber-alcantara/unverified"
},
{
"first": "Diego",
"last": "Feijó",
"id": "diego-feijo/unverified"
},
{
"first": "Viviane P.",
"last": "Moreira",
"id": "viviane-moreira"
}
],
"authors_old": "Cleber Alcântara | Viviane Moreira | Diego Feijo",
"authors_new": "Cleber de S. Alcântara | Diego Feijó | Viviane P. Moreira"
}
```

Use anthology_id 2020.lrec-1.531 from the issue body to locate the matching metadata entry, since no file path is provided. Start by searching the repo for that ID and compare the stored authors with `authors_old`. Apply the update to the matching record using the given `authors_new` value and ensure the old ordering is removed. Completion is just the corrected author string/order in the data.

Written by the indexing model from the issue text.