Adding supported adapters to hard_deletes (#6787)

Closes #6778

## What are you changing in this pull request and why?

`hard_deletes` works with these adapters:
dbt-postgres, dbt-bigquery, dbt-snowflake, dbt-redshift 

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<!-- vercel-deployment-preview -->
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🚀 Deployment available! Here are the direct links to the updated files:


-
https://docs-getdbt-com-git-runleonarun-patch-17-dbt-labs.vercel.app/reference/resource-configs/hard-deletes

<!-- end-vercel-deployment-preview -->

website/docs/reference/resource-configs/hard-deletes.md

@@ -48,7 +48,9 @@ snapshots:
 
 ## Description
 
-The `hard_deletes` config gives you more control on how to handle deleted rows from the source. Supported options are `ignore` (default), `invalidate` (replaces the legacy `invalidate_hard_deletes=true`), and `new_record`. Note that `new_record` will create a new metadata column in the snapshot table.
+The `hard_deletes` config gives you more control on how to handle deleted rows from the source. Supported options are `ignore` (default), `invalidate` (replaces the legacy `invalidate_hard_deletes=true`), and `new_record`. Note that `new_record` will create a new metadata column in the snapshot table. 
+
+You can use `hard_deletes` with dbt-postgres, dbt-bigquery, dbt-snowflake, and dbt-redshift adapters.
 
 import HardDeletes from '/snippets/_hard-deletes.md';