feat(ci): add copilot-setup-steps composite action

[Copilot]

Overview

This PR introduces a reusable GitHub Actions composite action called copilot-setup-steps that encapsulates common setup steps for Jekyll and GitHub Pages workflows. This action promotes code reusability and consistency across CI/CD pipelines.

What's New

Composite Action (.github/actions/copilot-setup-steps/)

A new composite action that provides:

• Automatic Repository Checkout: Uses actions/checkout@v4
• Ruby Environment Setup: Configurable Ruby version with automatic bundler caching
• GitHub Pages Configuration: Smart detection and configuration with graceful fallback
• Helpful Status Messages: Clear instructions when Pages is not enabled

Action Features

Inputs:

• ruby-version - Ruby version to use (default: 3.1)
• bundler-cache - Enable bundler caching (default: true)
• cache-version - Cache key version for invalidation (default: 0)

Outputs:

• pages-enabled - Boolean indicating if GitHub Pages is configured
• base-path - Base path for Jekyll build (when Pages is enabled)

Documentation

Action README (.github/actions/copilot-setup-steps/README.md)

• Comprehensive usage guide with examples
• Input/output reference tables
• Troubleshooting section
• Benefits and best practices

Example Workflow (.github/actions/copilot-setup-steps/example-workflow.yml)

• Complete working example showing how to use the action
• Demonstrates conditional logic based on action outputs
• Includes both build and deploy jobs

User Guide (_instructions/github-actions-copilot-setup.md)

• Detailed instruction following repository standards
• Multiple usage scenarios (basic, advanced, multi-Ruby testing)
• Best practices and common use cases
• Troubleshooting guide with solutions

Usage Example

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - name: Setup Environment
        id: setup
        uses: ./.github/actions/copilot-setup-steps
        with:
          ruby-version: '3.1'
      
      - name: Build with Jekyll
        run: |
          if [[ "${{ steps.setup.outputs.pages-enabled }}" == "true" ]]; then
            bundle exec jekyll build --baseurl "${{ steps.setup.outputs.base-path }}"
          else
            bundle exec jekyll build
          fi

Benefits

• ✅ DRY Principle: Eliminates duplicate setup code across workflows
• ✅ Consistency: Same environment setup across all CI/CD pipelines
• ✅ Maintainability: Update setup logic in one place
• ✅ Easy Integration: Simple to use with clear documentation
• ✅ Error Resilience: Graceful handling when GitHub Pages is not enabled

Files Changed

• Added .github/actions/copilot-setup-steps/action.yml - Composite action definition
• Added .github/actions/copilot-setup-steps/README.md - Action documentation
• Added .github/actions/copilot-setup-steps/example-workflow.yml - Usage example
• Added _instructions/github-actions-copilot-setup.md - User guide instruction

Testing

• ✅ YAML syntax validation passed
• ✅ Action metadata is properly structured
• ✅ Front matter follows repository instruction standards
• ✅ All required composite action elements present (inputs, outputs, runs)

This action can now be used across any Jekyll-based workflows in the repository to streamline CI/CD configuration.

Original prompt

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This section details on the original issue you should resolve

<issue_title>feat(ci): add copilot-setup-steps action</issue_title>
<issue_description></issue_description>

Comments on the Issue (you are @copilot in this section)

Fixes #7

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✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.

[Copilot]

Pull Request Overview

This PR introduces a reusable GitHub Actions composite action called copilot-setup-steps to standardize Jekyll and GitHub Pages setup across CI/CD workflows. The action encapsulates common setup steps including repository checkout, Ruby environment configuration, and GitHub Pages setup with graceful fallback handling.

• Adds a new composite action with configurable Ruby version, bundler caching, and cache versioning
• Provides clear outputs for conditional workflow logic based on GitHub Pages status
• Includes comprehensive documentation with usage examples and troubleshooting guides

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
.github/actions/copilot-setup-steps/action.yml	Composite action definition with inputs, outputs, and setup steps
.github/actions/copilot-setup-steps/README.md	Action documentation with usage examples and troubleshooting
.github/actions/copilot-setup-steps/example-workflow.yml	Complete example workflow demonstrating action usage
_instructions/github-actions-copilot-setup.md	Comprehensive user guide following repository instruction standards

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[Copilot]

Pull Request Overview

Copilot reviewed 4 out of 4 changed files in this pull request and generated no new comments.

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