Add indication for first time experience (#7044)

Author: williaml33

packaging/deb/postinst

@@ -13,6 +13,10 @@ The .NET Core Tools include a telemetry feature that collects usage information.
 
 The data collected is anonymous and will be published in an aggregated form for use by both Microsoft and community engineers under the Creative Commons Attribution License.
 
-The .NET Core Tools telemetry feature is enabled by default. You can opt-out of the telemetry feature by setting an environment variable DOTNET_CLI_TELEMETRY_OPTOUT (for example, 'export' on macOS/Linux, 'set' on Windows) to true (for example, 'true', 1). You can read more about .NET Core tools telemetry at https://aka.ms/dotnet-cli-telemetry."
+The .NET Core Tools telemetry feature is enabled by default. You can opt-out of the telemetry feature by setting an environment variable DOTNET_CLI_TELEMETRY_OPTOUT (for example, 'export' on macOS/Linux, 'set' on Windows) to true (for example, 'true', 1). You can read more about .NET Core tools telemetry at https://aka.ms/dotnet-cli-telemetry.
+
+Installation Note
+--------------
+A command will be run during the install process that will improve project restore speed and enable offline access. It will take up to a minute to complete."
 
 dotnet new > /dev/null 2>&1 || true

packaging/rpm/scripts/after_install_host.sh

@@ -17,6 +17,10 @@ The .NET Core Tools include a telemetry feature that collects usage information.
 
 The data collected is anonymous and will be published in an aggregated form for use by both Microsoft and community engineers under the Creative Commons Attribution License.
 
-The .NET Core Tools telemetry feature is enabled by default. You can opt-out of the telemetry feature by setting an environment variable DOTNET_CLI_TELEMETRY_OPTOUT (for example, 'export' on macOS/Linux, 'set' on Windows) to true (for example, 'true', 1). You can read more about .NET Core tools telemetry at https://aka.ms/dotnet-cli-telemetry."
+The .NET Core Tools telemetry feature is enabled by default. You can opt-out of the telemetry feature by setting an environment variable DOTNET_CLI_TELEMETRY_OPTOUT (for example, 'export' on macOS/Linux, 'set' on Windows) to true (for example, 'true', 1). You can read more about .NET Core tools telemetry at https://aka.ms/dotnet-cli-telemetry.
+
+Installation Note
+--------------
+A command will be run during the install process that will improve project restore speed and enable offline access. It will take up to a minute to complete."
 
 dotnet new > /dev/null 2>&1 || true