docs(image): added container labels (#25)

- [ ] Changes covered by unit and/or e2e tests;
- [ ] Documentation and examples updated;

## What this PR does / why we need it:
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What code changes are made?
What problem does this PR addresses, or what feature this PR adds?
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Added container labels to conform to OCI Labels Specification.

## Which issue(s) this PR resolves:
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Usage: `Resolves #<issue number>`, or `Resolves <link to the issue>`.
If PR is about `failing-tests`, please post the related tests in a
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Resolves #19

Signed-off-by: Nikola Borska <[email protected]>

.github/workflows/release.yaml

@@ -59,3 +59,11 @@ jobs:
           push: true
           tags: |
             ghcr.io/${{ github.event.repository.owner.name }}/scribe:${{ github.ref_name }}
+          labels: |
+            org.opencontainers.image.title="scribe"
+            org.opencontainers.image.authors="anza-labs contributors"
+            org.opencontainers.image.vendor="anza-labs"
+            org.opencontainers.image.license="Apache-2.0"
+            org.opencontainers.image.source="https://github.com/anza-labs/scribe"
+            org.opencontainers.image.base.name="gcr.io/distroless/static:nonroot"
+            org.opencontainers.image.created=${{ github.event.created_at }}