Added description of quantization_config (huggingface#31133)

* Description of quantization_config

Added missing description about quantization_config in replace_with_bnb_linear for better readability.

* Removed trailing spaces

src/transformers/integrations/bitsandbytes.py

@@ -243,6 +243,10 @@ def replace_with_bnb_linear(model, modules_to_not_convert=None, current_key_name
  An array to track the current key of the recursion. This is used to check whether the current key (part of
  it) is not in the list of modules to not convert (for instances modules that are offloaded to `cpu` or
  `disk`).
+ quantization_config ('transformers.utils.quantization_config.BitsAndBytesConfig'):
+ To configure and manage settings related to quantization, a technique used to compress neural network models
+ by reducing the precision of the weights and activations, thus making models more efficient in terms of both
+ storage and computation.
  """
  modules_to_not_convert = ["lm_head"] if modules_to_not_convert is None else modules_to_not_convert
  model, has_been_replaced = _replace_with_bnb_linear(