Create sk.json

[misa1515]

new slovak language

Proposed change

Type of change

• [ ] Bugfix
• [ ] New feature
• [ ] Code quality improvements to existing code or addition of tests
• [ ] Documentation

Additional information

Checklist

• [ ] The code change is tested and works locally.
• [ ] The code has been formatted using Black.
• [ ] Tests have been added to verify that the new code works.
• [ ] Documentation added/updated if required.

[tomaae]

This is not how translation works, see https://github.com/tomaae/homeassistant-truenas#translation I already added sk for you.