docs: Added details to Druid connection string (#20264)

* Added details to Druid connection string 

While linking Superset to Druid the correct connection string is very important however in the docs it is not well explained , so I added a little description to it

* Update druid.mdx

docs/docs/databases/druid.mdx

@@ -18,6 +18,12 @@ The connection string looks like:
 ```
 druid://<User>:<password>@<Host>:<Port-default-9088>/druid/v2/sql
 ```
+Here's a breakdown of the key components of this connection string:
+
+User: username portion of the credentials needed to connect to your database
+Password: password portion of the credentials needed to connect to your database
+Host: IP address (or URL) of the host machine that's running your database
+Port: specific port that's exposed on your host machine where your database is running
 
 ### Customizing Druid Connection