add python demo example

examples/hello-python/Dockerfile

@@ -0,0 +1,12 @@
+FROM python:3.9-alpine
+
+WORKDIR /usr/src/app
+
+COPY requirements.txt ./
+RUN pip install --no-cache-dir -r requirements.txt
+
+COPY . .
+
+CMD [ "python", "-m", "App.web" ]
+EXPOSE 8080
+