chore: create clean task branch

cards/src/cards/.gitkeep

cards/src/cards/App.java

duplicates/src/duplicates/.gitkeep

duplicates/src/duplicates/App.java

orders/.gitignore

orders/bin/orders/App.class

orders/bin/orders/Order.class

orders/src/orders/.gitkeep

orders/src/orders/App.java

orders/src/orders/Order.java