Updating image to work with arm/graviton

[wezell]

• Pins the NGINX version
• Changes linefeeds to \n
• pulls the appropriate s6 and envplate binaries based on the TARGETARCH.

It is missing the SHA verification per arch binary.

Setup

To enable "multiarch" building, you need to use docker buildx and have defined a new builder (you might need to enable "experimental" features in order to enable docker buildx). If you have buildx installed, you can see what buildx builders you have available by doing a ls:

docker buildx ls

To create and use a new multiarch builder run:

docker buildx create --name multiarch
docker buildx use multiarch