chore: update demo to the latest cookiecutter-robust-python

Author: 56kyle

build/lib/robust_python_demo/__init__.py

@@ -0,0 +1 @@
+"""Robust Python Demo."""

build/lib/robust_python_demo/__main__.py

@@ -0,0 +1,15 @@
+"""Command-line interface."""
+
+import typer
+
+
+app: typer.Typer = typer.Typer()
+
+
+@app.command(name="robust-python-demo")
+def main() -> None:
+    """Robust Python Demo."""
+
+
+if __name__ == "__main__":
+    app()  # pragma: no cover