Add automatic page title linking functionality

- Added autoLinkPageTitles() function to link page titles
- Added getAllPageTitles() to scan all content pages
- Added extractPageTitle() for MD/PHP/HTML files
- Added CSS styling for auto-links with dotted underline
- Page titles in content now automatically link to their pages
- Prevents linking inside existing HTML tags and links

templates/layout.html

@@ -162,6 +162,17 @@
         .site-info a:hover {
             text-decoration: underline;
         }
+        .auto-link {
+            color: #0d6efd;
+            text-decoration: none;
+            border-bottom: 1px dotted #0d6efd;
+            font-weight: 500;
+        }
+        .auto-link:hover {
+            color: #0a58ca;
+            text-decoration: none;
+            border-bottom-style: solid;
+        }
         .search-form {
             max-width: 300px;
         }