Added a batch_merge method [issue #1473]

Author: muddi900

gspread/worksheet.py

@@ -2728,6 +2728,23 @@ def merge_cells(self, name: str, merge_type: str = MergeType.merge_all) -> Any:
 
         return self.client.batch_update(self.spreadsheet_id, body)
 
+    def batch_merge(
+        self,
+        merges: List[Dict[Literal["range", "mergeType"], Union[str | MergeType]]],
+        merge_type: MergeType = MergeType.all,
+    ) -> Any:
+        requests = [
+            {
+                "merges": {
+                    "range": a1_range_to_grid_range(i["range"], self.id),
+                    "mergeType": i.get("mergeType", merge_type),
+                }
+            }
+            for i in merges
+        ]
+
+        return self.client.batch_update(self.spreadsheet_id, {"requests": requests})
+
     @cast_to_a1_notation
     def unmerge_cells(self, name: str) -> JSONResponse:
         """Unmerge cells.