Don't report an error if .vscode/settings.json doesn't exist

[JoshuaKGoldberg]

🐛 Bug Report

• tslint-to-eslint-config version: 0.4.0
• ESLint version: N/A
• Node version: N/A

Actual Behavior

λ npx tslint-to-eslint-config
❌ 1 error running tslint-to-eslint: ❌
Error: ENOENT: no such file or directory, open 'path\to\dir\.vscode\settings.json'

Expected Behavior

If the project doesn't have the file, don't complain.

Reproduction

In a new empty directory:

npx eslint --init
npx tslint-to-eslint-config