add python blinkie example

readme.md

@@ -18,6 +18,12 @@ a [dockerfile](./Dockerfile) and [compose file](./compose.yaml) have been provid
 keep in mind the commands will run in the docker container, too.
 you do not need to clone this repository to use the compose file provided.
 
+the docker image installs the python
+[`requests` library](https://docs.python-requests.org/en/latest/index.html),
+so you can use it for calling external APIs inside the container.
+
+the `pdweather` blinkie example does this.
+
 ### custom images
 
 to use utilities not installed in the standard docker image,