docs: add conformance status badges

[zhongkechen]

Summary

• add a README badge for the core conformance workflow
• add a README badge for the OpenTelemetry conformance workflow

Testing

• git diff --check
• confirmed both workflow paths are active on main

[github-actions]

Claude AI review

The Core Conformance badge will render "no status" rather than a pass/fail state. GitHub status badges (with no ?branch=/?event= query) reflect the most recent run on the default branch (main), but conformance-tests.yml only triggers on pull_request and workflow_dispatch (.github/workflows/conformance-tests.yml:7-14) — it has no push: branches: [main] trigger. pull_request runs are attributed to the PR head branch, not main, so nothing populates the default-branch status. Contrast this with the working ci.yml badge and the OpenTelemetry badge added just below, both of whose workflows include push: branches: [main].

Concrete fix: add a push: branches: ["main"] trigger to conformance-tests.yml (matching opentelemetry-conformance-tests.yml) so the badge reflects real status. Note that the conformance workflow deploys to shared AWS stacks under a global concurrency lock, so if running it on every push to main is undesirable, prefer removing this badge (or replacing it with one that points at a workflow that does run on main) rather than shipping a badge that permanently shows "no status".

[github-actions]

Codex AI review

No actionable findings. Both badge URLs match existing workflow filenames. Residual risk: live badge rendering and status responses were not network-validated.

Reviewed commit 67b1e84992bea4f87fb99c7c8aa1cdb83d3c05a1. Workflow run

[github-actions]

Claude AI review

This PR adds two README conformance badges. Both referenced workflow files exist and both badge/link URLs are well-formed. The OpenTelemetry Conformance badge will work correctly because opentelemetry-conformance-tests.yml triggers on push: branches: ["main"].

One actionable issue: the Core Conformance badge (README line 4) points at conformance-tests.yml, which only triggers on pull_request and workflow_dispatch — it never runs on push to main. GitHub status badges show the most recent run on the default branch, and pull_request runs are attributed to the PR head branch (not main), so this badge will render "no status" and defeat its stated purpose. See the inline comment on README.md:4.

Residual test risk: none beyond the badge-rendering behavior noted above; this is a docs-only change and cannot be exercised by the repo's test suites (verified in CI only after merge to main).

Reviewed commit 67b1e84992bea4f87fb99c7c8aa1cdb83d3c05a1. Workflow run