feat(Containerization): Update devcontainer to Ubuntu 24.04 with build tools

Switch from Debian Bullseye to Ubuntu 24.04 for CI alignment and fix
Python package compatibility issues with isort installation. Install
mdl for markdown linting, Python dependencies from tools/requirements.txt,
pre-commit hooks and yarn dependencies for website build. Add VS Code
markdown linting extension to devcontainer configuration.

Update README with quick start information for developers using the
devcontainer with IDEs supporting the devcontainer specification.

Closes: #623

Author: Marvin Gajek

.devcontainer/devcontainer.json

@@ -1,6 +1,6 @@
 {
 	"name": "Rucio-Docs",
-	"image": "mcr.microsoft.com/devcontainers/base:bullseye",
+	"image": "mcr.microsoft.com/devcontainers/base:ubuntu-24.04",
 	"features": {
 		"ghcr.io/devcontainers/features/docker-in-docker:2": {
 			"version": "latest",
@@ -10,5 +10,13 @@
 		"ghcr.io/devcontainers/features/node:1": {},
 		"ghcr.io/devcontainers/features/python:1": {},
 		"ghcr.io/devcontainers/features/ruby:1": {}
+	},
+	"postCreateCommand": "gem install mdl && python3 -m pip install --break-system-packages -r tools/requirements.txt pre-commit && cd website && yarn install",
+	"customizations": {
+		"vscode": {
+			"extensions": [
+				"davidanson.vscode-markdownlint"
+			]
+		}
 	}
-}
+}

README.md

@@ -8,6 +8,7 @@ links](https://github.com/rucio/documentation/actions/workflows/check_external_l
 This project contains the documentation for the **[Rucio](https://github.com/rucio/rucio)** data-management
 software.
 
+> **Quick Start**: A [devcontainer](.devcontainer/devcontainer.json) is available with all tools pre-installed. Open in IDEs supporting devcontainers (e.g. VS Code with Dev Containers extension).
 
 ## Contribution