Add DevContainer support

.devcontainer/Dockerfile

@@ -0,0 +1,33 @@
+#-------------------------------------------------------------------------------------------------------------
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License. See https://go.microsoft.com/fwlink/?linkid=2090316 for license information.
+#-------------------------------------------------------------------------------------------------------------
+
+FROM mcr.microsoft.com/dotnet/core/sdk:2.2.104
+
+# Avoid warnings by switching to noninteractive
+ENV DEBIAN_FRONTEND=noninteractive
+
+# Configure apt and install packages
+RUN apt-get update \
+    && apt-get -y install --no-install-recommends apt-utils 2>&1 \
+    #
+    # Verify git, process tools, lsb-release (common in install instructions for CLIs) installed
+    && apt-get -y install git procps lsb-release \
+    #
+    # Clean up
+    && apt-get autoremove -y \
+    && apt-get clean -y \
+    && rm -rf /var/lib/apt/lists/*
+
+RUN apt-get update \
+    && apt-get install curl gnupg apt-transport-https -y \
+    && curl https://packages.microsoft.com/keys/microsoft.asc | apt-key add - \
+    && echo "deb [arch=amd64] https://packages.microsoft.com/repos/microsoft-debian-stretch-prod stretch main" > /etc/apt/sources.list.d/microsoft.list \
+    && apt-get update \
+    && apt-get install -y powershell
+
+RUN pwsh -c Install-Module platyPS -Force; Install-Module Pester -Force
+
+# Switch back to dialog for any ad-hoc use of apt-get
+ENV DEBIAN_FRONTEND=dialog

.devcontainer/devcontainer.json

@@ -0,0 +1,12 @@
+// See https://aka.ms/vscode-remote/devcontainer.json for format details.
+{
+	"name": "C# (.NET Core 2.2) and PowerShell Core with platyPS and Pester",
+	"dockerFile": "Dockerfile",
+
+	"postCreateCommand": "dotnet restore",
+
+	"extensions": [
+		"ms-vscode.csharp",
+		"ms-vscode.powershell"
+	]
+}

.vscode/extensions.json

@@ -3,6 +3,7 @@
     // for the documentation about the extensions.json format
     "recommendations": [
         "ms-vscode.PowerShell",
-        "ms-vscode.csharp"
+        "ms-vscode.csharp",
+        "ms-vscode-remote.remote-containers"
     ]
 }