Merge pull request #6908 from segmentio/retl-sources-to-faq

Adding RETL source Q

Author: forstisabella

Diff for: src/connections/reverse-etl/index.md

@@ -354,6 +354,15 @@ Column JSON size | The maximum size of any single column value. | 128 KiB
 
 ## FAQs
 
+#### What warehouse data sources does Segment support?
+Segment supports the following sources: 
+* [Azure](/docs/connections/reverse-etl/reverse-etl-source-setup-guides/azure-setup/)
+* [BigQuery](/docs/connections/reverse-etl/reverse-etl-source-setup-guides/bigquery-setup/)
+* [Databricks](/docs/connections/reverse-etl/reverse-etl-source-setup-guides/databricks-setup/)
+* [Postgres](/docs/connections/reverse-etl/reverse-etl-source-setup-guides/postgres-setup/)
+* [Redshift](/docs/connections/reverse-etl/reverse-etl-source-setup-guides/redshift-setup/)
+* [Snowflake](/docs/connections/reverse-etl/reverse-etl-source-setup-guides/snowflake-setup/)
+
 #### Why do my sync results show *No records extracted* when I select *Updated records* after I enable the mapping? 
 It's expected that when you select **Updated records** the records do not change after the first sync. During the first sync, the reverse ETL system calculates a snapshot of all the results and creates records in the `_segment_reverse_etl` schema. All the records are considered as *Added records* instead of *Updated records* at this time. The records can only meet the *Updated records* condition when the underlying values change after the first sync completes.