[doc] fix typo in opt inference tutorial (#2849)

examples/tutorial/opt/inference/README.md

@@ -50,7 +50,7 @@ python opt_fastapi.py <model> --queue_size <QueueSize>
 ```
 The `<QueueSize>` can be an integer in `[0, MAXINT]`. If it's `0`, the request queue size is infinite. If it's a positive integer, when the request queue is full, incoming requests will be dropped (the HTTP status code of response will be 406).
 
-### Configure bathcing
+### Configure batching
 ```shell
 python opt_fastapi.py <model> --max_batch_size <MaxBatchSize>
 ```
@@ -85,4 +85,4 @@ Then open the web interface link which is on your console.
 See [script/processing_ckpt_66b.py](./script/processing_ckpt_66b.py).
 
 ## OPT-175B
-See [script/process-opt-175b](./script/process-opt-175b/).
\ No newline at end of file
+See [script/process-opt-175b](./script/process-opt-175b/).