This PR adds the ability for the ESLint language server (`eslint`) to be
controlled by the `language_servers` setting.
Now in your settings you can indicate that the ESLint language server
should be used for a given language, even if that language does not have
the ESLint language server registered for it already:
```json
{
"languages": {
"My Language": {
"language_servers": ["eslint", "..."]
}
}
}
```
Release Notes:
- N/A
Marshall Bowers
9ff847753e