New format for `contributors` in config file

I'm proposing this new format for `contributors` in config file to include JSON `key` with value of `username`.

### Why:

- This will significantly reduce the iteration in fetching old contributions.

#### Proposed format

```json

"contributors": [
"tenshiAMD": {
"login": "tenshiAMD",
"name": "Angel Aviel Domaoan",
"avatar_url": "https://avatars.githubusercontent.com/u/13580338?v=4",
"profile": "https://tenshiamd.com/",
"contributions": [
"code",
"design",
"security",
"data",
"mentoring"
]
}
]

```

#### Old format

```json
"contributors": [
{
"login": "tenshiAMD",
"name": "Angel Aviel Domaoan",
"avatar_url": "https://avatars.githubusercontent.com/u/13580338?v=4",
"profile": "https://tenshiamd.com/",
"contributions": [
"code",
"design",
"security",
"data",
"mentoring"
]
}
]
```