Add build instructions to README (fix issue #35)

README.md

@@ -2,4 +2,12 @@
 
 This repository provides examples for running robots using Space ROS
 
-Please refer to the [dockerfile repo](https://github.com/space-ros/docker/tree/main/space_robots) for running instruction
+Submissions to this repo should include:
+1) A Dockerfile or docker-compose.yaml file for building on top of the `osrf/space-ros:latest`
+2) A `build.sh` script for building the docker image
+    - This is required for CI to build the image
+    - See example here: https://github.com/space-ros/docker/blob/main/space_robots/build.sh
+3) A `run.sh` script for running the demo
+    - - See example here: https://github.com/space-ros/docker/blob/main/space_robots/run.sh
+
+Please refer to the [dockerfile repo](https://github.com/space-ros/docker/tree/main/space_robots) for instructions on running the existing demos