docs: note that query results already arrive as SmartArrays

The skip-ahead line told CMS Builder and ZenDB users the library was
installed but not that they were already holding SmartArrays with every
query. Say so, and point at the first usage section to see how they behave.

Author: daveedis

docs/getting-started.md

@@ -19,8 +19,9 @@ Contents:
 ## Installation
 
 Using CMS Builder or [ZenDB](https://github.com/interactivetools-com/ZenDB)?
-SmartArray is already installed; skip to
-[Your First SmartArray](#your-first-smartarray).
+SmartArray is already installed, and query results already arrive as
+SmartArrays; skip to [Your First SmartArray](#your-first-smartarray) to see
+how they behave.
 
 ```bash
 composer require itools/smartarray