Add devcontainer for development with VSCode

.devcontainer/Dockerfile

+
+FROM mcr.microsoft.com/vscode/devcontainers/javascript-node:14
+
+EXPOSE 9000
\ No newline at end of file

.devcontainer/devcontainer.json

+// For format details, see https://aka.ms/devcontainer.json. For config options, see the
+// README at: https://github.com/devcontainers/templates/tree/main/src/docker-existing-dockerfile
+{
+	"name": "amiv-admintool",
+	"build": {
+		"dockerfile": "Dockerfile"	
+	},
+	// Features to add to the dev container. More info: https://containers.dev/features.
+	// "features": {},
+
+	// Use 'forwardPorts' to make a list of ports inside the container available locally.
+	"forwardPorts": [9000],
+
+	// Uncomment the next line to run commands after the container is created.
+	"postCreateCommand": "npm install"
+
+	// Configure tool-specific properties.
+	// "customizations": {},
+
+	// Uncomment to connect as an existing user other than the container default. More info: https://aka.ms/dev-containers-non-root.
+	//"remoteUser": "node"
+}