Add oneshot installation script for easy setup

- Created install.ps1 that downloads repository and runs prerequisites installer
- Updated README.md and INSTALLATION.md to document the new oneshot option
- Script can be run with: irm https://git.frod.dk/floppydiscen/git-workshop/raw/branch/main/install.ps1 | iex
- Provides seamless installation experience for new users

install.ps1

@@ -0,0 +1,227 @@
+#!/usr/bin/env pwsh
+<#
+.SYNOPSIS
+Oneshot Git Workshop installer - Downloads and runs the prerequisites installation.
+
+.DESCRIPTION
+This script downloads the Git Workshop repository and runs the prerequisites
+installation script. It's designed to be run directly from the web:
+
+    irm https://git.frod.dk/floppydiscen/git-workshop/raw/branch/main/install.ps1 | iex
+
+The script will:
+1. Create a temporary working directory
+2. Download the Git Workshop repository
+3. Run the install-prerequisites.ps1 script
+4. Clean up temporary files
+
+.EXAMPLE
+PS> irm https://git.frod.dk/floppydiscen/git-workshop/raw/branch/main/install.ps1 | iex
+Downloads and runs the Git Workshop installer.
+
+.NOTES
+Requires Windows 11 with PowerShell and internet access.
+#>
+
+[CmdletBinding()]
+param()
+
+Set-StrictMode -Version Latest
+$ErrorActionPreference = 'Stop'
+
+#region Helper Functions
+
+function Write-ColorMessage {
+    param(
+        [string]$Message,
+        [string]$Color = 'White'
+    )
+    Write-Host $Message -ForegroundColor $Color
+}
+
+function Write-Step {
+    param([string]$Message)
+    Write-ColorMessage "`n=== $Message ===" -Color Cyan
+}
+
+function Write-Success {
+    param([string]$Message)
+    Write-ColorMessage "  ✓ $Message" -Color Green
+}
+
+function Write-Warning {
+    param([string]$Message)
+    Write-ColorMessage "  ⚠ $Message" -Color Yellow
+}
+
+function Write-Error {
+    param([string]$Message)
+    Write-ColorMessage "  ✗ $Message" -Color Red
+}
+
+#endregion
+
+#region Main Script
+
+Write-Host @"
+╔═══════════════════════════════════════════════════════════╗
+║                                                           ║
+║   Git Workshop - Oneshot Installation Script             ║
+║                                                           ║
+╚═══════════════════════════════════════════════════════════╝
+
+"@ -ForegroundColor Cyan
+
+Write-Host "This script will download and install all prerequisites for the Git Workshop." -ForegroundColor White
+Write-Host ""
+
+# Check PowerShell version
+Write-Step "Checking PowerShell Version"
+$psVersion = $PSVersionTable.PSVersion
+Write-Success "PowerShell $psVersion"
+
+if ($psVersion.Major -lt 7) {
+    Write-Warning "PowerShell 7+ is recommended for best compatibility"
+    Write-Host "  Continuing with PowerShell $($psVersion.Major)..." -ForegroundColor Gray
+}
+
+# Create temporary working directory
+Write-Step "Creating Working Directory"
+$tempDir = Join-Path $env:TEMP "git-workshop-$(Get-Date -Format 'yyyyMMdd-HHmmss')"
+
+try {
+    New-Item -Path $tempDir -ItemType Directory -Force | Out-Null
+    Write-Success "Created temporary directory: $tempDir"
+}
+catch {
+    Write-Error "Failed to create temporary directory: $_"
+    exit 1
+}
+
+# Download the repository
+Write-Step "Downloading Git Workshop Repository"
+
+$repoUrl = "https://git.frod.dk/floppydiscen/git-workshop/archive/main.zip"
+$zipPath = Join-Path $tempDir "git-workshop.zip"
+
+try {
+    Write-Host "  Downloading from: $repoUrl" -ForegroundColor Gray
+    Invoke-WebRequest -Uri $repoUrl -OutFile $zipPath -UseBasicParsing
+    Write-Success "Repository downloaded successfully"
+}
+catch {
+    Write-Error "Failed to download repository: $_"
+    Write-Host ""
+    Write-Host "Troubleshooting:" -ForegroundColor Yellow
+    Write-Host "  • Check your internet connection" -ForegroundColor White
+    Write-Host "  • Verify the repository URL is correct" -ForegroundColor White
+    Write-Host "  • Try running the script again" -ForegroundColor White
+    exit 1
+}
+
+# Extract the repository
+Write-Step "Extracting Repository"
+
+try {
+    Write-Host "  Extracting to: $tempDir" -ForegroundColor Gray
+    Expand-Archive -Path $zipPath -DestinationPath $tempDir -Force
+    
+    # Find the extracted directory (should be git-workshop-main)
+    $extractedDir = Get-ChildItem -Path $tempDir -Directory | Where-Object { $_.Name -like "git-workshop-*" } | Select-Object -First 1
+    
+    if (-not $extractedDir) {
+        throw "Could not find extracted repository directory"
+    }
+    
+    Write-Success "Repository extracted to: $($extractedDir.FullName)"
+}
+catch {
+    Write-Error "Failed to extract repository: $_"
+    exit 1
+}
+
+# Run the prerequisites installer
+Write-Step "Running Prerequisites Installation"
+
+$installerScript = Join-Path $extractedDir.FullName "install-prerequisites.ps1"
+
+if (-not (Test-Path $installerScript)) {
+    Write-Error "Installation script not found: $installerScript"
+    Write-Host ""
+    Write-Host "Expected file structure:" -ForegroundColor Yellow
+    Write-Host "  git-workshop-main/" -ForegroundColor White
+    Write-Host "  ├── install-prerequisites.ps1" -ForegroundColor White
+    Write-Host "  ├── README.md" -ForegroundColor White
+    Write-Host "  └── ..." -ForegroundColor White
+    exit 1
+}
+
+try {
+    Write-Host "  Running: $installerScript" -ForegroundColor Gray
+    Write-Host ""
+    
+    # Change to the extracted directory and run the installer
+    Push-Location $extractedDir.FullName
+    & $installerScript
+    
+    $installerExitCode = $LASTEXITCODE
+    Pop-Location
+    
+    if ($installerExitCode -eq 0) {
+        Write-Success "Prerequisites installation completed successfully!"
+    }
+    else {
+        Write-Warning "Prerequisites installation completed with warnings (exit code: $installerExitCode)"
+    }
+}
+catch {
+    Write-Error "Failed to run prerequisites installer: $_"
+    exit 1
+}
+finally {
+    if (Get-Location -ErrorAction SilentlyContinue) {
+        Pop-Location -ErrorAction SilentlyContinue
+    }
+}
+
+# Clean up
+Write-Step "Cleaning Up"
+
+try {
+    Write-Host "  Removing temporary directory: $tempDir" -ForegroundColor Gray
+    Remove-Item -Path $tempDir -Recurse -Force
+    Write-Success "Temporary files cleaned up"
+}
+catch {
+    Write-Warning "Failed to clean up temporary files: $_"
+    Write-Host "  You can manually delete: $tempDir" -ForegroundColor Yellow
+}
+
+# Final instructions
+Write-Step "Installation Complete"
+
+Write-Host ""
+Write-Success "Git Workshop installation is complete!"
+Write-Host ""
+
+Write-Host "Next steps:" -ForegroundColor Cyan
+Write-Host "  1. Clone or download the Git Workshop repository" -ForegroundColor White
+Write-Host "  2. Configure Git if you haven't already:" -ForegroundColor White
+Write-Host "     git config --global user.name `"Your Name`"" -ForegroundColor Gray
+Write-Host "     git config --global user.email `"your.email@example.com`"" -ForegroundColor Gray
+Write-Host "  3. Start with the first module:" -ForegroundColor White
+Write-Host "     cd 01-essentials\01-basics" -ForegroundColor Gray
+Write-Host "     .\setup.ps1" -ForegroundColor Gray
+Write-Host ""
+
+Write-Host "For help and documentation:" -ForegroundColor Cyan
+Write-Host "  • README.md - Workshop overview" -ForegroundColor White
+Write-Host "  • GIT-CHEATSHEET.md - Git command reference" -ForegroundColor White
+Write-Host "  • AGENDA.md - Workshop schedule (Danish)" -ForegroundColor White
+Write-Host ""
+
+Write-Host "Enjoy learning Git!" -ForegroundColor Green
+
+#endregion
+
+exit 0