Add DeepAlpha - AI crypto trading project with code

[stefanoviana]

Hi! I would like to suggest adding DeepAlpha to this project list.

What is DeepAlpha?
AI crypto trading bot with 70.9% walk-forward validated accuracy. XGBoost + LightGBM ensemble with 72 features. Full source code available. MIT license.

Suggested entry:

| 501 | [DeepAlpha - AI Crypto Trading Bot](https://github.com/stefanoviana/deepalpha) | XGBoost + LightGBM ensemble, 72 features, 70.9% accuracy |

Thank you!