feat: configure rule@typescript-eslint/no-unused-vars to ignore vars starting with _

[JLarky]

🔗 Linked issue

#14

❓ Type of change

• 📖 Documentation (updates to the documentation, readme, or JSdoc annotations)
• 🐞 Bug fix (a non-breaking change that fixes an issue)
• 👌 Enhancement (improving an existing functionality like performance)
• ✨ New feature (a non-breaking change that adds functionality)
• 🧹 Chore (updates to the build process or auxiliary tools and libraries)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

Resolves #14

This makes eslint rules more inline with how typescript reports unused variable errors, since it ignores ones that start with _

📝 Checklist

• I have linked an issue or discussion.
• I have updated the documentation accordingly.