Refactor: Replace sidebar with horizontal navigation bar

- Remove sidebar and toggle functionality
- Add Bootstrap navbar with dropdown menus
- Move navigation to top between header and content
- Update menu rendering for Bootstrap dropdowns
- Clean up unused files (header.mustache, sidebar.mustache, sidebar.js)
- Add guide link with book icon in footer
- Simplify layout structure
- Remove duplicate code and fix syntax errors
- Add .gitignore for node_modules and other temp files

engine/core/config.php

@@ -1,16 +1,8 @@
 <?php
-
+ 
 return [
     'site_title' => 'CodePress',
-    'site_description' => 'A simple PHP CMS',
-    'base_url' => '/',
     'content_dir' => __DIR__ . '/../../content',
     'templates_dir' => __DIR__ . '/../templates',
-    'cache_dir' => __DIR__ . '/../../cache',
-    'default_page' => 'home',
-    'error_404' => '404',
-    'markdown_enabled' => true,
-    'php_enabled' => true,
-    'bootstrap_version' => '5.3.0',
-    'jquery_version' => '3.7.1'
+    'default_page' => 'home'
 ];