new app: National Day Calendar (US)

[jvivona]

Show what national day(s) it is according to The National Day Calendar at https://nationaldaycalendar.com

[tidbyt]

⚠️ The automated review process is experimental and likely has bugs. Please bear with us as we iron out the kinks and enable you to ship changes at high velocity 🚀

Next Steps

Hello! Thank you so much for your change 🤜 🤛 . There are a few things you need to do:

• Sign the CLA if you haven't already
• Ensure your build is green! Any problem will display a proposed solution to try out
• Get a review, either by Tidbyt Bot or by a Tidbyt engineer

Manual Review Required

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	Test	Details
✅	App Dir	All files are in a single app directory
🟡	Modules	Usage of random.star requires review
✅	Original Author	The original author matches the PR author