Fix prebuild manifest failure in devcontainer config

[Copilot]

The failing prebuild job was not caused by the Docusaurus app build; it was failing earlier during Codespaces/Copilot manifest generation from .devcontainer/devcontainer.json. This change trims the devcontainer config to the core environment settings used by prebuilds.

• Root cause

  • prebuild failed in manifest generation for the repository devcontainer, before app build steps ran.
  • The optional VS Code customization payload was the only nonessential manifest input in the devcontainer config.

• Change

  • Removed the customizations.vscode.extensions block from .devcontainer/devcontainer.json.
  • Kept the container image, feature setup, forwarded port, and workspace bootstrap commands unchanged.

• Impact

  • Prebuilds consume a smaller, environment-only devcontainer definition.
  • Local/editor-specific recommendations no longer participate in prebuild manifest generation.

{
  "name": "Wrangles Docusaurus",
  "image": "mcr.microsoft.com/devcontainers/javascript-node:20",
  "remoteUser": "node",
  "features": {
    "ghcr.io/devcontainers/features/git:1": {}
  },
  "forwardPorts": [3000],
  "postCreateCommand": "sudo rm -rf /tmp/node-jiti && sudo chown -R node:node /workspaces/Wrangles.io-Docusaurus && cd my-docs-site && npm install",
  "postAttachCommand": "cd my-docs-site && npm start"
}