Docker (Desktop) must be installed & running in order for the .yml to work
Download this .yml into your project folder. After that, open terminal and cd into the folder.
Type: docker-compose up -d
It should download required images (mariadb, wordpress), and create new Docker volumes/containers automatically.
After progress is done, it should display [+] Running 5/5 with no errors.
Check the Docker app for logs, etc.