## Complete Multi-language System & Navigation Enhancement

### Features Added:
- **Multi-language Support**: Dutch/English with URL-based switching (?lang=nl|en)
- **Theme Customization**: Configurable header/navigation colors via config.json
- **Navigation Improvements**: Active states, dropdown chevron icons, visual distinction
- **Mobile Responsive**: Separate desktop/mobile search layouts
- **Template System**: Fixed rendering pipeline for all partials

### Technical Fixes:
- Fixed language file path (engine/lang/ vs engine/core/class/../lang/)
- Added template data rendering to layout template
- Implemented navigation active state for default/home page
- Added chevron icons to dropdown folders for visual distinction
- Removed hardcoded navigation opacity class for theme colors

### Files Modified:
- config.json: Added theme and language configuration
- engine/core/class/CodePressCMS.php: Multi-language and navigation logic
- engine/templates/: Enhanced header, footer, navigation, layout
- engine/lang/: Dutch and English translation files
- public/assets/css/mobile.css: Mobile responsive fixes

### Result:
Fully functional multi-language CMS with proper navigation states and theme customization.

engine/lang/nl.php

@@ -0,0 +1,26 @@
+<?php
+return [
+    'site_title' => 'CodePress',
+    'home' => 'Home',
+    'search' => 'Zoeken',
+    'search_placeholder' => 'Zoeken...',
+    'search_button' => 'Zoeken',
+    'welcome' => 'Welkom',
+    'created' => 'Aangemaakt',
+    'modified' => 'Aangepast',
+    'author' => 'Auteur',
+    'manual' => 'Handleiding',
+    'no_content' => 'Geen inhoud gevonden',
+    'no_results' => 'Geen resultaten gevonden',
+    'results_found' => 'resultaten gevonden',
+    'breadcrumb_home' => 'Home',
+    'file_details' => 'Bestandsdetails',
+    'guide' => 'Handleiding',
+    'powered_by' => 'Mogelijk gemaakt door',
+    't_powered_by' => 'Mogelijk gemaakt door',
+    'directory_empty' => 'Deze map is leeg',
+    'page_not_found' => 'Pagina niet gevonden',
+    'page_not_found_text' => 'De pagina die u zoekt bestaat niet.',
+    'mappen' => 'Mappen',
+    'paginas' => 'Pagina\'s'
+];