add filter_by_page helper to NotionSearch

Author: markacola

src/models/search.rs

@@ -346,6 +346,12 @@ impl NotionSearch {
             value: FilterValue::Database,
         }
     }
+    pub fn filter_by_pages() -> Self {
+        Self::Filter {
+            property: FilterProperty::Object,
+            value: FilterValue::Page,
+        }
+    }
 }
 
 impl From<NotionSearch> for SearchRequest {