docs: update bulk update bruno docs with normalization examples

Update Bulk Update Books.bru to demonstrate tag and contributor updates:
- Add tags update example with normalized output
- Add contributors update example
- Shows punctuation preference behavior

Demonstrates that tags and contributors are automatically normalized
when updated via bulk operations, ensuring consistency across the database.

Relates to Tags & Contributors Migration documentation updates

bruno/books/Bulk Update Books.bru

@@ -29,22 +29,24 @@
       "Content-Type": "application/json",
       "Authorization": "Bearer {{authToken}}"
     },
-    "body": {
-      "updates": [
-        {
-          "book_id": "{{bookId1}}",
-          "updates": {
-            "title": "Updated Title",
-            "genre": "Science Fiction"
-          }
-        },
-        {
-          "book_id": "{{bookId2}}",
-          "updates": {
-            "author": "Updated Author"
-          }
-        }
-      ]
-    }
+     "body": {
+       "updates": [
+         {
+           "book_id": "{{bookId1}}",
+           "updates": {
+             "title": "Updated Title",
+             "genre": "Science Fiction",
+             "tags": ["science fiction", "non-fiction", "ACME CORP."]
+           }
+         },
+         {
+           "book_id": "{{bookId2}}",
+           "updates": {
+             "author": "Updated Author",
+             "contributors": ["O'Reilly Media", "Penguin Random House"]
+           }
+         }
+       ]
+     }
   }
 }