You actually don't need this repository to try it out. The docker image built from this is automatically available from the Docker Hub.
First, you'll need to install Docker if you don't already have it.
Then,
docker pull openaustralia/mapit-australia
docker run -p 8020:80 -d openaustralia/mapit-australia
Point your web browser to http://localhost:8020 and you should MapIt Australia.
Find areas over the point (150.3,-33.7) which is roughly Katoomba, NSW
The postcode 2780
All areas that intersect postcode 2780
All Commonwealth Electoral Divisions that intersect 2780.