feat: update favicon to use favicon.png file

- Change favicon from kdebug-logo.png to favicon.png for better browser compatibility
- Add apple-touch-icon for iOS/macOS devices
- Improve website branding consistency with dedicated favicon file

Author: timkrebs

_includes/head.html

@@ -4,7 +4,8 @@
   <meta name="viewport" content="width=device-width, initial-scale=1">
   {%- seo -%}
   <link rel="stylesheet" href="{{ "/assets/main.css" | relative_url }}">
-  <link rel="icon" type="image/png" href="{{ '/assets/images/kdebug-logo.png' | relative_url }}">
+  <link rel="icon" type="image/png" href="{{ '/assets/images/favicon.png' | relative_url }}">
+  <link rel="apple-touch-icon" href="{{ '/assets/images/favicon.png' | relative_url }}">
   {%- feed_meta -%}
   {%- if jekyll.environment == 'production' and site.google_analytics -%}
     {%- include google-analytics.html -%}