Fix guide template variable replacement and enhance documentation

- Fix template variable replacement in guide pages by removing {{}} brackets
- Escape code blocks in guide markdown to prevent template processing
- Completely rewrite guide documentation with comprehensive CMS features
- Add bilingual guide support (English/Dutch) with detailed examples
- Enhance CodePressCMS core with improved guide page handling
- Update template system with better layout and footer components
- Improve language files with additional translations
- Update configuration with enhanced theme and language settings

Resolves issue where guide pages were showing replaced template variables
instead of displaying them as documentation examples.

config.json

@@ -8,7 +8,9 @@
         "header_color": "#0a369d",
         "header_font_color": "#ffffff",
         "navigation_color": "#2754b4",
-        "navigation_font_color": "#ffffff"
+        "navigation_font_color": "#ffffff",
+        "sidebar_background": "#f8f9fa",
+        "sidebar_border": "#dee2e6"
     },
     "language": {
         "default": "nl",
@@ -19,9 +21,8 @@
         "keywords": "cms, php, content management, file-based"
     },
     "author": {
-        "name": "Edwin Noorlander",
-        "website": "https://noorlander.info",
-        "git": "https://git.noorlander.info/E.Noorlander/CodePress.git"
+        "name": "E. Noorlander",
+        "website": "https://noorlander.info"
     },
     "features": {
         "auto_link_pages": true,