.eslintrc.js does not have suggestions

[isidorn]

Refs #11100

1. Simple repo, initiazlie eslint, .eslintrc.js gets created
2. Open .eslintrc.js and triggere intelli-sense -> no suggestions
3. As found while discussing with @dbaeumer the issue here is that this file is .js and not .json
4. I would expect suggestions to help me set this file up

[dbaeumer]

Might be hard to achieve since we need to tell the tsserver about a d.ts eslint file under the cover. On top of this we would need to maintain such a file.

[dbaeumer]

This issue was moved to microsoft/vscode-eslint#124