Nit: install documentation broken

[joncamp]

Documentation assumes you have already cloned repo, and the mkdir command won't work unless you alredy have a ws directory (which presumably you don't since the repo doesn't have one). suggested updates below

git clone https://github.com/polyhobbyist/jetbot
cd jetbot
mkdir -p ws/src
vcs import ws/src < jetbot.repos
sudo docker-compose -f Docker-compose.yaml up # sudo may not be necessary, depending on your configuration