Add Podman usage documentation for devcontainer

[gerchowl]

Description

Add documentation for using the devcontainer with Podman in three different ways. Currently, the repository only has the .devcontainer/devcontainer.json file, but users may want to use Podman directly instead of VS Code/Cursor's built-in devcontainer support.

Tasks

Option 1: Direct Podman CLI Usage

• Add quickstart section to README with proper command order:
  • Start container with correct volume mounts and working directory
  • Run initialization scripts in correct order (post-create.sh, post-attach.sh)
  • Include proper SELinux context (:Z flag for Linux systems)

Example command:

podman run -it --rm \
  -v "${PWD}:/workspace:Z" \
  -w /workspace \
  ghcr.io/morepet/containers/dev/typst:1.3-dev \
  /bin/bash

# Then manually run:
/workspace/.devcontainer/post-create.sh
/workspace/.devcontainer/post-attach.sh

Option 2: Podman Compose

• Create podman-compose.yml file in repository root
• Document the compose file in README similar to Option 1
• Include instructions for starting: podman-compose up -d

Proposed compose file:

version: '3'
services:
  dev:
    image: ghcr.io/morepet/containers/dev/typst:1.3-dev
    volumes:
      - .:/workspace:cached
    working_dir: /workspace
    command: /bin/bash
    stdin_open: true
    tty: true

Option 3: Dev Container CLI

• Add section to README about using @devcontainers/cli
• Document installation: npm install -g @devcontainers/cli
• Document usage: devcontainer up --workspace-folder . --docker-path podman
• Note that this option provides the most complete devcontainer.json compatibility

Success Criteria

• All three options are documented in README
• Users can choose the option that best fits their workflow
• Instructions include proper script execution order
• SELinux considerations are mentioned for Linux users