Update links and availability notice of Payment Services schema

[keharper]

Purpose of this pull request

This PR updates the Payment Services GraphQL reference documentation to reflect availability on Adobe Commerce as a Cloud Service (SaaS) and consolidates field-level details into the dedicated API reference. Changes span all Payment Services queries and mutations:

• Updated the availability note on all 11 pages to state that the API is available automatically on SaaS, while Adobe Commerce on Cloud and on-premises deployments require Payment Services 2.10.0 or higher.
• Updated all Reference section links from /reference/graphql/index.md to /reference/graphql/saas/index.md.
• Removed inline Input attributes and Output attributes tables, deferring field-level details to the API reference. The getPaymentConfig page replaces its attribute tables with a Related information section linking to external PayPal and Adobe documentation.
• Relocated the PayPal currency codes link in createPaymentOrder to appear before the Syntax section for better context.
• Added a Reference section to completeOrder, which previously had none.

Affected pages

• https://developer.adobe.com/commerce/webapi/graphql/payment-services-extension/mutations/add-products-new-cart
• https://developer.adobe.com/commerce/webapi/graphql/payment-services-extension/mutations/complete-order
• https://developer.adobe.com/commerce/webapi/graphql/payment-services-extension/mutations/create-payment-order
• https://developer.adobe.com/commerce/webapi/graphql/payment-services-extension/mutations/create-vault-card-payment-token
• https://developer.adobe.com/commerce/webapi/graphql/payment-services-extension/mutations/create-vault-card-setup-token
• https://developer.adobe.com/commerce/webapi/graphql/payment-services-extension/mutations/set-cart-inactive
• https://developer.adobe.com/commerce/webapi/graphql/payment-services-extension/mutations/sync-payment-order
• https://developer.adobe.com/commerce/webapi/graphql/payment-services-extension/queries/get-payment-config
• https://developer.adobe.com/commerce/webapi/graphql/payment-services-extension/queries/get-payment-order
• https://developer.adobe.com/commerce/webapi/graphql/payment-services-extension/queries/get-payment-sdk
• https://developer.adobe.com/commerce/webapi/graphql/payment-services-extension/queries/get-vault-config

What's New highlights

whatsnew
Updated all Payment Services GraphQL query and mutation topics to document SaaS availability, point to the updated API reference, and remove inline field tables in favor of the dedicated reference pages.

[github-actions]

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Generated: 2026-06-08T17:38:26.821Z
Mode: Full Linting (all rules + dead links check)
Target Directory: /home/runner/work/commerce-webapi/commerce-webapi
Skipped Rules:
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[github-actions]

🔍 Linter Report

Click to expand full report

═══════════════════════════════════════════════════════════════
                     LINTER REPORT
═══════════════════════════════════════════════════════════════

Generated: 2026-06-08T17:52:59.714Z
Mode: Full Linting (all rules + dead links check)
Target Directory: /home/runner/work/commerce-webapi/commerce-webapi
Skipped Rules:
  - check-frontmatter → src/pages/includes
  - missing-heading → src/pages/includes

───────────────────────────────────────────────────────────────

Files to process: 566


═══════════════════════════════════════════════════════════════
                        SUMMARY
═══════════════════════════════════════════════════════════════

  📁 Files processed:    566
  📄 Files with issues:  0
  ❌ Total errors:       0
  ⚠️  Total warnings:     0
  📋 Total issues:       0

Result: ✅ PASSED - All files passed linting successfully!

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