docs - druid jdbc and json unfolding (#43267)

docs/data-modeling/json-unfolding.md

@@ -61,3 +61,4 @@ For example, if you upload a CSV with JSON in it, you might need to update the d
 
 - [PostgreSQL](../databases/connections/postgresql.md)
 - [MySQL](../databases/connections/mysql.md)
+- [Druid (JDBC)](../databases/connections/druid.md)

docs/databases/connections/druid.md

@@ -8,6 +8,10 @@ To add a database connection, click on the **gear** icon in the top right, and n
 
 Fill out the fields for that database, and click **Save changes** at the bottom.
 
+## Select "Druid JBDC"
+
+Prefer the Druid JDBC connection.
+
 ## Settings
 
 You can edit these settings at any time. Just remember to save your changes.
@@ -28,6 +32,14 @@ The database port (e.g, 8082).
 
 See our [guide to SSH tunneling](../ssh-tunnel.md).
 
+### Allow unfolding of JSON columns
+
+> Only available for the Druid JDBC connection.
+
+This enables unfolding of JSON columns into their component fields.
+
+See [JSON unfolding](../../data-modeling/json-unfolding.md).
+
 ### Re-run queries for simple explorations
 
 Turn this option **OFF** if people want to click **Run** (the play button) before applying any [Summarize](../../questions/query-builder/introduction.md#grouping-your-metrics) or filter selections.