🔨 re-added VS Code devcontainer config

ref #108

.devcontainer/Dockerfile

@@ -0,0 +1,2 @@
+ARG VARIANT="14-buster"
+FROM mcr.microsoft.com/vscode/devcontainers/javascript-node:0-${VARIANT}

.devcontainer/devcontainer.json

@@ -0,0 +1,24 @@
+{
+	"name": "Node.js",
+	"build": {
+		"dockerfile": "Dockerfile",
+		"args": {
+			"VARIANT": "14"
+		}
+	},
+	"settings": {
+		"terminal.integrated.shell.linux": "/bin/bash"
+	},
+	"extensions": [
+		"dbaeumer.vscode-eslint",
+		"2gua.rainbow-brackets",
+		"christian-kohler.npm-intellisense",
+		"remimarsal.prettier-now",
+		"svelte.svelte-vscode",
+		"lokalise.i18n-ally",
+		"fivethree.vscode-svelte-snippets",
+		"voorjaar.windicss-intellisense"
+	],
+	"postCreateCommand": "yarn",
+	"remoteUser": "node"
+}