Billing: update MP committed spend page

[Blargian]

Summary

Updates for the marketplace committed spend page.

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	Updated (UTC)
clickhouse-docs	Ready	Preview	Nov 13, 2025 10:11am

[Blargian]

@rsickles tagging for review: https://clickhouse-docs-6e34b9t7o-clickhouse.vercel.app/docs/cloud/billing/marketplace/aws-marketplace-committed-contract

[rsickles]

@Blargian some additional edits added here cc @dominictran

[Blargian]

Thanks @rsickles, updated with latest changes.