refactor: Add .devcontainer files for Ruby development

.devcontainer/Dockerfile

@@ -0,0 +1,8 @@
+# Released under the MIT License.
+# Copyright, 2023, by Aristóteles Coutinho.
+
+# [Choice] Ruby version: 3, 3.0, 2, 2.7, 2.6
+ARG VARIANT="3"
+FROM mcr.microsoft.com/devcontainers/ruby:${VARIANT}
+
+RUN apt-get update

.devcontainer/devcontainer.json

@@ -1,11 +1,11 @@
 // For format details, see https://aka.ms/devcontainer.json. For config options, see the
 // README at: https://github.com/devcontainers/templates/tree/main/src/ruby
 {
-	"name": "Lennarb",
+	"name": "Lennarb project development",
 	// Or use a Dockerfile or Docker Compose file. More info: https://containers.dev/guide/dockerfile
 	// "image": "mcr.microsoft.com/devcontainers/ruby:1-3.2-bullseye"
 	"build": {
-		"dockerfile": "../Dockerfile"
+		"dockerfile": "Dockerfile"
 	}
 	// Features to add to the dev container. More info: https://containers.dev/features.
 	// "features": {},