Update secure-kinesis.md to address feedback

[Blargian]

Summary

Updates this guide to address user feedback, and make some formatting improvements.

Checklist

• Delete items not relevant to your PR
• URL changes should add a redirect to the old URL via https://github.com/ClickHouse/clickhouse-docs/blob/main/docusaurus.config.js
• If adding a new integration page, also add an entry to the integrations list here: https://github.com/ClickHouse/clickhouse-docs/blob/main/docs/integrations/index.mdx

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Project	Deployment	Preview	Comments	Updated (UTC)
clickhouse-docs	Ready	Preview		Sep 30, 2025 2:43pm

3 Skipped Deployments

Project	Deployment	Preview	Comments	Updated (UTC)
clickhouse-docs-jp	Ignored			Sep 30, 2025 2:43pm
clickhouse-docs-ru	Ignored	Preview		Sep 30, 2025 2:43pm
clickhouse-docs-zh	Ignored	Preview		Sep 30, 2025 2:43pm