Add a .devcontainer

Co-authored-by: NNed Schwartz <ned@theinterned.net>

.devcontainer/Dockerfile

+# See here for image contents: https://github.com/microsoft/vscode-dev-containers/tree/v0.222.0/containers/javascript-node/.devcontainer/base.Dockerfile
+
+# [Choice] Node.js version (use -bullseye variants on local arm64/Apple Silicon): 16, 14, 12, 16-bullseye, 14-bullseye, 12-bullseye, 16-buster, 14-buster, 12-buster
+ARG VARIANT="16"
+FROM mcr.microsoft.com/vscode/devcontainers/javascript-node:0-${VARIANT}
+
+# [Optional] Uncomment this section to install additional OS packages.
+# RUN apt-get update && export DEBIAN_FRONTEND=noninteractive \
+#     && apt-get -y install --no-install-recommends <your-package-list-here>
+
+# [Optional] Uncomment if you want to install an additional version of node using nvm
+# ARG EXTRA_NODE_VERSION=10
+# RUN su node -c "source/usr/local/share/nvm/nvm.sh && nvm install ${EXTRA_NODE_VERSION}"
+
+# [Optional] Uncomment if you want to install more global node modules
+# RUN su node -c "npm install -g <your-package-list-here>" 

.devcontainer/devcontainer.json

+// For format details, see https://aka.ms/devcontainer.json. For config options, see the README at:
+// https://github.com/microsoft/vscode-dev-containers/tree/v0.222.0/containers/javascript-node
+{
+	"name": "Node.js",
+	"build": {
+		"dockerfile": "Dockerfile",
+		// Update 'VARIANT' to pick a Node version: 16, 14, 12.
+		// Append -bullseye or -buster to pin to an OS version.
+		// Use -bullseye variants on local arm64/Apple Silicon.
+		"args": { "VARIANT": "16" }
+	},
+
+	// 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": {
+		"git": "latest"
+	}
+}