fix typo

Author: yanliu1111

video_notebooks/01_pytorch_workflow_video.ipynb

@@ -816,7 +816,7 @@
         "  loss.backward()\n",
         "\n",
         "  # 5. Step the optimizer (perform gradient descent)\n",
-        "  optimizer.step() # by default how the optimizer changes will acculumate through the loop so... we have to zero them above in step 3 for the next iteration of the loop\n",
+        "  optimizer.step() # by default how the optimizer changes will accumulate through the loop so... we have to zero them above in step 3 for the next iteration of the loop\n",
         "\n",
         "  ### Testing\n",
         "  model_0.eval() # turns off different settings in the model not needed for evaluation/testing (dropout/batch norm layers)\n",
@@ -2297,4 +2297,4 @@
       "outputs": []
     }
   ]
-}
+}