docs: update docs for "Live Update" with Postgres example (#967)

Author: georgeh0

docs/docs/core/flow_methods.mdx

@@ -190,7 +190,7 @@ A data source may enable one or multiple *change capture mechanisms*:
 *   Configured with a [refresh interval](flow_def#refresh-interval), which is generally applicable to all data sources.
 
 *   Specific data sources also provide their specific change capture mechanisms.
-    For example, [`AmazonS3` source](../ops/sources/#amazons3) watches S3 bucket's change events, and [`GoogleDrive` source](../ops/sources#googledrive) allows polling recent modified files.
+    For example, [`Postgres` source](../ops/sources/#postgres) listens to PostgreSQL's change notifications, [`AmazonS3` source](../ops/sources/#amazons3) watches S3 bucket's change events, and [`GoogleDrive` source](../ops/sources#googledrive) allows polling recent modified files.
     See documentations for specific data sources.
 
 Change capture mechanisms enable CocoIndex to continuously capture changes from the source data and update the target data accordingly, under live update mode.