Adding databricks materialization (#4211)

## What are you changing in this pull request and why?
Adding link to Databricks materializations to migration guide

## Checklist

- [x] Review the [Content style
guide](https://github.com/dbt-labs/docs.getdbt.com/blob/current/contributing/content-style-guide.md)
and [About
versioning](https://github.com/dbt-labs/docs.getdbt.com/blob/current/contributing/single-sourcing-content.md#adding-a-new-version)
so my content adheres to these guidelines.
- [x] Add a checklist item for anything that needs to happen before this
PR is merged, such as "needs technical review" or "change base branch."

website/docs/guides/migration/versions/01-upgrading-to-v1.6.md

@@ -59,7 +59,7 @@ Supported on:
 - [Postgres](/reference/resource-configs/postgres-configs#materialized-view)
 - [Redshift](/reference/resource-configs/redshift-configs#materialized-view)
 - [Snowflake](/reference/resource-configs/snowflake-configs#dynamic-tables)
-- Databricks (docs forthcoming)
+- [Databricks](/reference/resource-configs/databricks-configs#materialized-views-and-streaming-tables)
 
 Support for BigQuery coming soon.