Implement docker-release-action with prefixed images and reusable workflows

[Copilot]

This PR implements a complete GitHub Action for building and pushing multi-platform Docker images, following the template patterns from php-composer-testing-action and infrastructure repositories as requested in the issue.

Key Features Implemented

🐳 Multi-platform Docker Image Building

• Supports linux/amd64 and linux/arm64 by default with configurable platforms
• Uses Docker Buildx for efficient multi-architecture builds
• Integrates with GitHub Container Registry (GHCR) by default, with support for other registries

🏷️ Configurable Image Prefixes

• Allows adding custom prefixes to image names (e.g., myorg- creates myorg-myapp)
• Handles different registry formats intelligently:
  • GHCR: ghcr.io/{owner}/{prefix}{image-name}
  • Docker Hub: docker.io/{prefix}{image-name}

🔄 Reusable Workflows

• Composite action for direct use in workflows
• Reusable workflow template for consistent multi-repo usage
• Supports both single image builds and multi-image projects

Implementation Details

The action follows the composite action pattern from php-composer-testing-action:

• Uses runs.using: "composite" structure
• Includes proper input validation and defaults
• Provides meaningful outputs (image name and digest)

The Docker build process mirrors the infrastructure repository workflows:

• QEMU setup for multi-platform builds
• Docker Buildx configuration
• Metadata extraction for proper tagging
• Registry authentication handling

Usage Examples

Basic Usage

- uses: RevoTale/docker-release-action@v1
  with:
    image-name: my-app

With Custom Prefix

- uses: RevoTale/docker-release-action@v1
  with:
    image-name: api
    image-prefix: mycompany-
    context: ./api

As Reusable Workflow

jobs:
  docker:
    uses: RevoTale/docker-release-action/.github/workflows/reusable.yml@v1
    with:
      image-name: my-app
      image-prefix: org-

Files Added

• action.yml - Main composite action definition
• .github/workflows/reusable.yml - Reusable workflow template
• .github/workflows/major-version.yml - Version management (from php-composer-testing-action)
• .github/workflows/test.yml - Testing workflow
• examples/ - Complete usage examples for different scenarios
• Dockerfile and test/Dockerfile - Test infrastructure
• Updated README.md with comprehensive documentation

The implementation is fully tested with Docker builds and YAML validation, ensuring it works correctly across different use cases while maintaining the minimal, focused approach requested.

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