update README

mlu_370-piper/piper/Makefile

@@ -0,0 +1,13 @@
+.PHONY: clean docker
+
+all:
+	cmake -Bbuild -DCMAKE_INSTALL_PREFIX=install
+	cmake --build build --config Release
+	cd build && ctest --config Release
+	cmake --install build
+
+docker:
+	docker buildx build . --platform linux/amd64,linux/arm64,linux/arm/v7 --output 'type=local,dest=dist'
+
+clean:
+	rm -rf build install dist