docs: fix catalog support link in README

[TokenStyle]

Description

Fixes the broken Catalog Support link in README.md.

The link used a site-root-relative path, which resolves against whichever host renders the file. On GitHub, and on the PyPI project page that renders this README as the package description, it pointed at https://github.com/integrations/dbt/features-and-configurations and returned 404. The path was also out of date with respect to the docs site, missing /docs and most of the current path.

Replaced it with the absolute URL, matching the documentation link already used earlier in the same README.

Before:

](/integrations/dbt/features-and-configurations#catalog-support)

After:

](https://clickhouse.com/docs/integrations/connectors/data-ingestion/etl-tools/dbt/features-and-configurations#catalog-support)

The equivalent paragraph in docs/index.mdx on the codex/vendor-dbt-clickhouse-docs branch (#728) already uses the current path, so this only brings the README copy back in line. A root-relative path stays correct there, since that file is rendered by the docs site, while the README needs the absolute form. The two changes touch different parts of README.md and do not conflict.

Testing

Documentation only, no Python changed, so make lint and the test suite do not apply. Verified that the previous target returns 404 and that the new URL returns 200 with the catalog-support anchor present on the page.

Closes #732

[CLAassistant]

All committers have signed the CLA.

[koletzilla]

Thanks for the PR!