add missing makefile

example/extend_polars_python_dispatch/Makefile

@@ -0,0 +1,25 @@
+
+SHELL=/bin/bash
+
+venv:  ## Set up virtual environment
+	python3 -m venv venv
+	venv/bin/pip install -r requirements.txt
+
+install: venv
+	unset CONDA_PREFIX && \
+	source venv/bin/activate && maturin develop -m extend_polars/Cargo.toml
+
+install-release: venv
+	unset CONDA_PREFIX && \
+	source venv/bin/activate && maturin develop --release -m extend_polars/Cargo.toml
+
+clean:
+	-@rm -r venv
+	-@cd extend_polars && cargo clean
+
+
+run: install
+	source venv/bin/activate && python run.py
+
+run-release: install-release
+	source venv/bin/activate && python run.py