feat: add page up/down hotkeys for quick bookmark input

docs/tools/bookmark.md

@@ -28,6 +28,7 @@ The bookmark editor gives you full control over PDF navigation bookmarks (also c
 - Import bookmarks from CSV (title, page, level) or JSON files
 - Export bookmarks to CSV or JSON for external editing
 - Bookmark styling: color (red, blue, green, yellow, purple) and font style (bold, italic, bold italic)
+- Quick navigation: scroll through pages with page up/down keys
 
 ## Options
 

src/js/logic/bookmark-pdf.ts

@@ -1057,6 +1057,12 @@ document.addEventListener('keydown', (e: KeyboardEvent) => {
       e.preventDefault();
       redo();
     }
+  } else if (e.key === 'PageUp') {
+    e.preventDefault();
+    prevPageBtn?.click();
+  } else if (e.key === 'PageDown') {
+    e.preventDefault();
+    nextPageBtn?.click();
   }
 });