docs: Add Elasticsearch unsigned_long → UInt64 type mapping

[claudespice]

Summary

Add the unsigned_long row to the Elasticsearch type-mapping table now that the connector decodes it explicitly to Arrow UInt64.

Source PRs

• Expand Arrow type handling in formatting and Elasticsearch spiceai#10825 — Expand Arrow type handling in formatting and Elasticsearch

Changes

• website/docs/components/data-connectors/elasticsearch/index.md
  • Add unsigned_long → UInt64 to the type-mapping table, with a note that the decoder accepts both numeric values and digit-string representations (since JS clients commonly serialize values > 2^53-1 as strings).

Test plan

• cd website && npm run build passes locally
• Type-mapping arm verified in source diff (Some("unsigned_long") => DataType::UInt64)

[github-actions]

✅ Pull with Spice Passed

Passing checks:

• ✅ Title meets minimum length requirement (10 characters)
• ✅ Has at least one of the required labels: area/blog, area/docs, area/cookbook, dependencies
• ✅ No banned labels detected
• ✅ Has at least one assignee: claudespice

[github-actions]

✅ Pull with Spice Passed

Passing checks:

• ✅ Title meets minimum length requirement (10 characters)
• ✅ Has at least one of the required labels: area/blog, area/docs, area/cookbook, dependencies
• ✅ No banned labels detected
• ✅ Has at least one assignee: claudespice

[github-actions]

🚀 deployed to https://00e334dd.spiceai-org-website.pages.dev

[github-actions]

🚀 deployed to https://4b8252bc.spiceai-org-website.pages.dev