message: Update hugectr_user_guide.md
  Fixing a bug on document by adding "lambda" to regularization sample code.
diff: @@ -398,7 +398,7 @@ For example:
  ```
  -* **Loss**: Computes the current loss value based on the model outputs and the true labels based on the given inputs. You can specify which `regularization` is used to train your model here. By default, no regularization will be used.
  +* **Loss**: Computes the current loss value based on the model outputs and the true labels based on the given inputs. You can specify which `regularization` is used to train your model here. By default, no regularization will be used. Both "L1" and "L2" Regularization are supported in HugeCTR. Please **Note** that `lambda` should be also specified together with 'regularizer'.
  For example:
  ```json
  @@ -434,6 +434,7 @@ For example:
  "type": "BinaryCrossEntropyLoss",
  "bottom": ["fc8","label"],
  "regularizer": "L2",
  + "lambda": 0.01,
  "top": "loss"
  }
  