FlashCards_v3.0.0

• ✨ Implemented a spaced repetition algorithm
• 🐛 Severely buffed out automated test suite
• 🔨 Updated the build instructions
• ✅ Added ruff to enforce a code formatting standard
• 📚 Set up automatically generated documentation via GH actions
• 🔥 Removed files that should have been in a gitignore all along