expand and clarify mssql-cli install instructions

Author: dzsquared

docs/tools/mssql-cli.md

@@ -17,14 +17,43 @@ monikerRange: "=azuresqldb-current||=azure-sqldw-latest||>=sql-server-2016||=sql
 
 [!INCLUDE[appliesto-ss-asdb-asdw-xxx-md](../includes/appliesto-ss-asdb-asdw-xxx-md.md)]
 
-mssql-cli is an interactive command-line tool for querying SQL Server, install it on Windows, macOS, or Linux.
+mssql-cli is an interactive command-line tool for querying SQL Server and runs on Windows, macOS, or Linux.
 
 ## Install mssql-cli
 
-For detailed installation instructions, see the [Installation Guide](https://github.com/dbcli/mssql-cli/tree/master/doc/installation), or if you know pip, install by running the following command:
+For detailed installation instructions, see the [Installation Guide](https://github.com/dbcli/mssql-cli/tree/master/doc/installation). The most common install scenarios are summarized below.
+
+### Windows and macOS Installation
+
+mssql-cli is installed on Windows and macOS using `pip`:
 
 ```$ pip install mssql-cli```
 
+For more detailed instructions, please see the [Installation Guide](https://github.com/dbcli/mssql-cli/tree/master/doc/installation).
+
+### Linux Installation
+
+After registering the Microsoft repository, mssql-cli can be installed and upgraded through package managers on several Linux distributions.
+
+The following example applies to Ubuntu 18.04 (Bionic), more information and examples for other distributions can be found in the [Installation Guide](https://github.com/dbcli/mssql-cli/tree/master/doc/installation).
+
+```
+# Import the public repository GPG keys
+curl https://packages.microsoft.com/keys/microsoft.asc | sudo apt-key add -
+
+# Register the Microsoft Ubuntu repository
+sudo apt-add-repository https://packages.microsoft.com/ubuntu/18.04/prod
+
+# Update the list of products
+sudo apt-get update
+
+# Install mssql-cli
+sudo apt-get install mssql-cli
+
+# Install missing dependencies
+sudo apt-get install -f
+```
+
 ## mssql-cli documentation
 
 Documentation for mssql-cli is located in the [mssql-cli GitHub repository](https://github.com/dbcli/mssql-cli).