Run the following commands:
git clone https://github.com/CatalystCode/drones-for-good
cd drones-for-good
git submodule init
git submodule update
You can work on each repo separately as you would any other repo.
You can also work on the submodules from this parent clone, and commit the changes:
cd drones-for-good-demo
git checkout master
git add .
git commit -m "changes made to..."
git push origin master
Once you include updates and push them, you need to update the refs on the parent repo:
git submodule foreach git pull origin master
git add .
git commit -m "sub modules updated"
git push origin master