docs: Add Docker deployment instructions and build script

- Add build-and-push-docker.ps1 PowerShell script for automated Docker builds
- Update README.md with comprehensive Docker deployment guide
- Include environment variable configuration
- Document automated email scheduling in containers
- Add GitHub Container Registry push instructions

build-and-push-docker.ps1

@@ -0,0 +1,32 @@
+# Docker Build and Push Script for Prayer App
+# Run this script to build and push the Docker container to GitHub Container Registry
+
+Write-Host "🔨 Building Docker image..." -ForegroundColor Green
+docker build -t ghcr.io/nmemmert/prayer-app:latest .
+
+if ($LASTEXITCODE -eq 0) {
+    Write-Host "✅ Docker image built successfully!" -ForegroundColor Green
+
+    Write-Host "🔐 Logging into GitHub Container Registry..." -ForegroundColor Yellow
+    Write-Host "Please enter your GitHub Personal Access Token (with package write permissions):" -ForegroundColor Yellow
+    $token = Read-Host -AsSecureString
+    $tokenPlain = [Runtime.InteropServices.Marshal]::PtrToStringAuto([Runtime.InteropServices.Marshal]::SecureStringToBSTR($token))
+
+    echo $tokenPlain | docker login ghcr.io -u nmemmert --password-stdin
+
+    if ($LASTEXITCODE -eq 0) {
+        Write-Host "🚀 Pushing Docker image to GitHub Container Registry..." -ForegroundColor Green
+        docker push ghcr.io/nmemmert/prayer-app:latest
+
+        if ($LASTEXITCODE -eq 0) {
+            Write-Host "✅ Docker image pushed successfully!" -ForegroundColor Green
+            Write-Host "🌐 Your container is now available at: ghcr.io/nmemmert/prayer-app:latest" -ForegroundColor Cyan
+        } else {
+            Write-Host "❌ Failed to push Docker image" -ForegroundColor Red
+        }
+    } else {
+        Write-Host "❌ Failed to login to GitHub Container Registry" -ForegroundColor Red
+    }
+} else {
+    Write-Host "❌ Failed to build Docker image" -ForegroundColor Red
+}