Added Mandelbrot app

[scriptorum]

This app has numerous time checks to prevent the 30 second timeout and improve quality within the time allotted. However, after working on this for weeks, I find that pixlet check has a one second time out! Despite likely failing that automated check, I hope you'll accept it anyway, as it looks pretty cool on my Tidbyt. :)

I have read the CLA Document and I hereby sign the CLA

[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

Hang tight! A Tidbyt engineer will be by shortly to review your change. Here is what they will be looking for:

	Test	Details
🟡	App Dir	File 'apps/mandelbrot/screenshots/m1.gif' is in apps/mandelbrot/screenshots
🟡	Modules	Usage of random.star requires review
✅	Original Author	The original author matches the PR author

[scriptorum]

@matslina Is the 1 second check mandatory?