docs: add devcontainer setup instructions to CONTRIBUTING.md

Added documentation for using development containers as an alternative
environment setup method, including both VS Code Dev Containers and
GitHub Codespaces options.

Generated with Continue (https://continue.dev)

Co-Authored-By: Continue <noreply@continue.dev>
Co-authored-by: nate <nate@continue.dev>

.devcontainer/devcontainer.json

@@ -0,0 +1,4 @@
+{
+  "image": "mcr.microsoft.com/devcontainers/universal:2",
+  "features": {}
+}

CONTRIBUTING.md

@@ -113,7 +113,32 @@ process as welcoming and straightforward as possible.
 
 ### Environment Setup
 
-#### Pre-requisites
+#### Option 1: Development Container (Recommended for Quick Start)
+
+The easiest way to get started is using a development container, which provides a pre-configured environment:
+
+1. **Prerequisites**:
+
+   - [Docker Desktop](https://www.docker.com/products/docker-desktop) or compatible container runtime
+   - [VS Code](https://code.visualstudio.com/) with the [Dev Containers extension](https://marketplace.visualstudio.com/items?itemName=ms-vscode-remote.remote-containers)
+   - OR [GitHub Codespaces](https://github.com/features/codespaces) (no local installation required)
+
+2. **Using VS Code Dev Containers**:
+
+   - Clone the repository
+   - Open the project in VS Code
+   - When prompted, click "Reopen in Container" (or run `Dev Containers: Reopen in Container` from the command palette)
+   - VS Code will build the container and set up the environment automatically
+
+3. **Using GitHub Codespaces**:
+   - Navigate to the Continue repository on GitHub
+   - Click the green "Code" button and select "Codespaces"
+   - Click "Create codespace on main" (or your branch)
+   - Your development environment will be ready in minutes
+
+#### Option 2: Local Setup
+
+**Pre-requisites**
 
 You should have Node.js version 20.19.0 (LTS) or higher installed. You can get it
 on [nodejs.org](https://nodejs.org/en/download) or, if you are using NVM (Node Version Manager), you can set the correct