Update AdventureWorks description in README

Clarify description of AdventureWorks sample database.

Author: MashaMSFT

README.md

@@ -10,7 +10,7 @@ Please note that specific features, such as In-Memory OLTP, are edition-specific
 Releases provide convenient downloads of sample databases and applications, eliminating the need to build them from source code. This SQL Server samples repository offers the following notable releases:
 
   - [Wide World Importers sample database v1.0](https://github.com/Microsoft/sql-server-samples/releases/tag/wide-world-importers-v1.0) is the main sample for SQL Server 2016 and Azure SQL Database. It contains both an OLTP and an OLAP database.
-  - [AdventureWorks](https://github.com/Microsoft/sql-server-samples/releases/tag/adventureworks)
+  - [AdventureWorks](https://github.com/Microsoft/sql-server-samples/releases/tag/adventureworks) is a sample database with OLTP, data warehouse and lightweight database options.
   - [In-Memory OLTP Performance Demo v1.0](https://github.com/Microsoft/sql-server-samples/releases/tag/in-memory-oltp-demo-v1.0) illustrates the performance benefits of the In-Memory OLTP technology built into SQL Server and Azure SQL Database.
   - [IoT Smart Grid sample v1.0](https://github.com/Microsoft/sql-server-samples/releases/tag/iot-smart-grid-v1.0) illustrates how SQL Server can be leveraged to ingest data from IoT devices and sensors, and how you can run analytics on that data.