[Workers] Add distribution heatmaps changelog

[ZinMK]

Summary

• announce distribution heatmaps for Workers Observability
• explain how heatmaps support investigation of performance issues
• include a screenshot of the heatmap experience

Testing

• pnpm exec prettier --check src/content/changelog/workers/2026-08-28-distribution-heatmaps.mdx
• pnpm run check
• verified the local changelog preview returns HTTP 200

[cloudflare-docs-bot]

Review

⚠️ 1 warning found in commit e361f57.

👉 Fix in your agent 👈

Fix the following review findings in PR #33097 (https://github.com/cloudflare/cloudflare-docs/pull/33097).

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---

## Style Guide Review

### Warnings (1)

#### SG-8826973f6ca2 · Use Markdown image syntax for content images
- **File:** `src/content/changelog/workers/2026-08-28-distribution-heatmaps.mdx` line 15
- **Issue:** Lines 15-18 use a raw `<img>` tag to render the changelog screenshot.
- **Fix:** Use Markdown image syntax and remove the import: `![Workers Observability distribution heatmap for request latency, showing relative event density and hover details for a selected region.](~/assets/images/changelog/workers/observability/2026-08-28-distribution-heatmaps.png)`.

Code Review

This code review is in beta and may not always be helpful — use your judgment.

_{No code review issues found.}

Conventions

_{No convention issues found.}

Style Guide Review

Warnings (1)

File	Issue
changelog/workers/2026-08-28-distribution-heatmaps.mdx line 15	Use Markdown image syntax for content images — Lines 15-18 use a raw <img> tag to render the changelog screenshot. Fix: Use Markdown image syntax and remove the import: .

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