Enhance lab sheets with action item styling and installation guide

- Added a new Action Items Guide to provide styling classes for highlighting important sections in lab sheets.
- Introduced an INSTALL.md file detailing Jekyll installation and testing procedures.
- Implemented action item and warning item styles in the main stylesheet for better visual distinction.
- Updated lab content to utilize new action item classes for clarity and emphasis on critical instructions.
- Enhanced JavaScript functionality to process custom highlight syntax in lab content.

test-jekyll.sh

@@ -0,0 +1,40 @@
+#!/bin/bash
+
+# Test script for Jekyll installation and site building
+
+echo "🔍 Checking Ruby installation..."
+if command -v ruby &> /dev/null; then
+    echo "✅ Ruby is installed: $(ruby --version)"
+else
+    echo "❌ Ruby is not installed. Please install Ruby first."
+    echo "   See INSTALL.md for installation instructions."
+    exit 1
+fi
+
+echo ""
+echo "🔍 Checking Bundler installation..."
+if command -v bundle &> /dev/null; then
+    echo "✅ Bundler is installed: $(bundle --version)"
+else
+    echo "❌ Bundler is not installed. Installing..."
+    gem install bundler
+fi
+
+echo ""
+echo "🔍 Installing dependencies..."
+bundle install
+
+echo ""
+echo "🔍 Building Jekyll site..."
+if bundle exec jekyll build; then
+    echo "✅ Site built successfully!"
+    echo ""
+    echo "🔍 Starting Jekyll server..."
+    echo "📱 Site will be available at: http://localhost:4000"
+    echo "🛑 Press Ctrl+C to stop the server"
+    echo ""
+    bundle exec jekyll serve --livereload
+else
+    echo "❌ Site build failed. Check the error messages above."
+    exit 1
+fi