build(devcontainer): install dependencies

Author: schlich

.devcontainer/devcontainer.json

@@ -0,0 +1,16 @@
+{
+	"name": "Docker in Docker",
+	"image": "mcr.microsoft.com/devcontainers/base:bullseye",
+	"features": {
+		"ghcr.io/devcontainers/features/docker-in-docker:2": {}
+	},
+	"customizations": {
+		"vscode": {
+			"settings": {
+				"git.detectSubmodulesLimit": 15
+			}
+		}
+	},
+	// "postCreateCommand": "./openslides setup && docker compose pull"
+	// "postCreateCommand": "wget https://github.com/OpenSlides/openslides-manage-service/releases/download/latest/openslides && chmod +x openslides"
+}