adding support for github codespaces.

.devcontainer/devcontainer.json

@@ -0,0 +1,31 @@
+// For format details, see https://aka.ms/devcontainer.json. For config options, see the README at:
+// https://github.com/microsoft/vscode-dev-containers/tree/v0.233.0/containers/javascript-node
+{
+	"name": "Node.js",
+	"build": {
+		"dockerfile": "Dockerfile",
+		// Update 'VARIANT' to pick a Node version: 18, 16, 14.
+		// Append -bullseye or -buster to pin to an OS version.
+		// Use -bullseye variants on local arm64/Apple Silicon.
+		"args": { "VARIANT": "16-bullseye" }
+	},
+
+	// Set *default* container specific settings.json values on container create.
+	"settings": {},
+
+	// Add the IDs of extensions you want installed when the container is created.
+	"extensions": ["dbaeumer.vscode-eslint"],
+
+	// Use 'forwardPorts' to make a list of ports inside the container available locally.
+	// "forwardPorts": [],
+
+	// Use 'postCreateCommand' to run commands after the container is created.
+	// "postCreateCommand": "yarn install",
+
+	// Comment out to connect as root instead. More info: https://aka.ms/vscode-remote/containers/non-root.
+	"remoteUser": "node",
+	"features": {
+		"docker-in-docker": "20.10",
+		"github-cli": "latest"
+	}
+}