Add support for multiple Docker platforms

[stevep-arm]

This change should make the image multi-plaform.

There is a chance it will also need qemu setting up.

    - name: Set up QEMU
      uses: docker/setup-qemu-action@v3

BEGIN_COMMIT_OVERRIDE
feat: Add support for multiple Docker platforms
END_COMMIT_OVERRIDE

[Jason3S]

@stevep-arm,

Thank you. I need to make sure this is not a breaking change. If it is, it might need to wait until the next version.

[stevep-arm]

The way that it works under the hood is that it builds two images and there's a manifest that takes the place of the current single image. The client uses the manifest to decide which image it prefers and download it. I've done a similar change before (kovetskiy/mark#420). They did already have the QEMU part defined so my only query is whether that is necessary.

[stevep-arm]

❯ docker manifest inspect ghcr.io/streetsidesoftware/cspell:9.4.0
{
   "schemaVersion": 2,
   "mediaType": "application/vnd.oci.image.index.v1+json",
   "manifests": [
      {
         "mediaType": "application/vnd.oci.image.manifest.v1+json",
         "size": 1999,
         "digest": "sha256:e7832be1ec7ad82ea381d3791d9cbf12a8b02dd903071d2c3b6616f840ab7bb5",
         "platform": {
            "architecture": "amd64",
            "os": "linux"
         }
      },
      {
         "mediaType": "application/vnd.oci.image.manifest.v1+json",
         "size": 1999,
         "digest": "sha256:e0ef46d6e7817965c982d573022aa2e73d730eba627f0f1189a9d5f3504b019b",
         "platform": {
            "architecture": "arm64",
            "os": "linux"
         }
      },
      {
         "mediaType": "application/vnd.oci.image.manifest.v1+json",
         "size": 567,
         "digest": "sha256:9d5ba57b694ac00ead11a03c194af19b6ed793bb85c2e090ac129eb30cea64bf",
         "platform": {
            "architecture": "unknown",
            "os": "unknown"
         }
      },
      {
         "mediaType": "application/vnd.oci.image.manifest.v1+json",
         "size": 567,
         "digest": "sha256:7611eaa20b6304892147efb4ec22a4a80e395fd548fd0ef0ddca110609a7d3bd",
         "platform": {
            "architecture": "unknown",
            "os": "unknown"
         }
      }
   ]
}

Thanks! 🎉