Demonstrate how to use NixPacks to build containers.
NOTES:
- Nixpacks simplify using nix for installing software but they seem to create massive images.
# install nixpacks
brew install railwayapp/tap/nixpacks
# show options
nixpacks # build ffmpeg
nixpacks build . --name nixpack_example --start-cmd "ffmpeg --version"
# run
docker run -it nixpack_example