'babel-eslint' deprecation and rename

Babel's eslint parser has been moved into their main monorepo, and republished under a different name:

* Deprecation on npm: https://www.npmjs.com/package/babel-eslint
* Old repository archived: https://github.com/babel/babel-eslint
* New location: https://github.com/babel/babel/tree/main/eslint/babel-eslint-parser

Because the name is different, eslintrc configuration settings will need to change from
```
"parser": "babel-eslint",
```
to
```
"parser": "@babel/eslint-parser",
```
Making this change to this plugin's recommended config seems to me like a breaking change.

`babel-eslint` still seems to work fine, even with recent babels, but it's been a year since it's had updates and I assume something will break eventually.