Update time-series-filling-gaps.md

[flavh]

Fix typo in 'INTERPPOLATE' clause

Summary

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

[vercel]

@flavh is attempting to deploy a commit to the ClickHouse Team on Vercel.

A member of the Team first needs to authorize it.

[vercel]

The latest updates on your projects. Learn more about Vercel for Git ↗︎

1 Skipped Deployment

Name	Status	Preview	Comments	Updated (UTC)
clickhouse-docs-zh	⬜️ Ignored (Inspect)	Visit Preview		Mar 27, 2025 2:51pm

[CLAassistant]

All committers have signed the CLA.

[gingerwizard]

merging. @Blargian curious how this made it past spellcheck