Add otel-trace-context to the configmap docs

[javorszky]

Proposed changes

This is the documentation that goes with nginx/kubernetes-ingress#10843

Adds the otel-trace-context configmap option's documentation.

Tested locally with make watch, looks good.

Checklist

Before sharing this pull request, I completed the following checklist:

• I read the Contributing guidelines
• My branch adheres to the Git conventions
• My content changes adhere to the F5 Technical Writing Style Guide
• If my changes involve potentially sensitive information¹, I have assessed the possible impact
• I have waited to ensure my changes pass tests, and addressed any discovered issues

Footnotes

1. Potentially sensitive information includes personally identify information (PII), authentication credentials, and live URLs. Refer to the style guide for guidance about placeholder content. ↩

[github-actions]

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[promptless]

Promptless style review

Thanks for adding this, @javorszky. The row lands in the right place next to the other otel-* keys, links to the upstream otel_trace_context directive, and lists all four accepted values correctly. I checked it against the implementing change (nginx/kubernetes-ingress#10843) and the key name, the required otel-exporter-endpoint dependency, and the value set all match.

Style: No blocking style issues. One minor consistency nit: the description cell doesn't end with a period, while the sibling rows do. Consider adding one after ignore (cite: tables — parallel structure within a column).

Technical accuracy (listed separately for SME verification): See the inline comment on the Default column value. I don't correct technical content myself. Please confirm it with a subject matter expert.

Categories checked in full: voice-and-tone, grammar, punctuation, formatting (tables, italics, capitalization), terminology (word-list, f5-product-names). Skipped: accessibility, media, error-messages, security. The change adds no image, error string, or sensitive data.

Reading level: The added row is a short reference entry, well within the target reading level. No complexity concerns.

Submitting as a comment rather than an approval only because of the technical-accuracy question above. That's a call for the maintainer, not a blocker.