Publish Docker images for more architectures

[ngosang]

Related #14

You should publish more images => https://github.com/DRuggeri/alertmanager_gotify_bridge/blob/master/.github/workflows/release.yml#L128

Just some example, I don't know archs supported by go => linux/386,linux/amd64,linux/arm/v5,linux/arm/v7,linux/arm64/v8,linux/mips64le,linux/ppc64le,linux/s390x

[DRuggeri]

Hi, @ngosang. I'm not opposed, but there's a matrix of support that needs to be maintained:

• The golang os/arch combo
• The linux arch reported in uname -m
• The docker/build-push-actions supported versions

I'm more than happy to add these if you can identify the different permutations of each value and toss a pull request out there. In practice, I find that nearly all users are able to be served with:

• AMD64 (64-bit x86)
• ARM64 (newer ARMv8 instruction set)
• ARM (ARMv7 and prior instruction set)

[ngosang]

@DRuggeri thank you. This is enough for me. I tested x64 and arm architectures and both are right!