message: Add bullet points so Reduction values are clearer
diff: @@ -39,13 +39,14 @@ class Reduction(object):
  """Types of loss reduction.
  Contains the following values:
  - `NONE`: Un-reduced weighted losses with the same shape as input.
  - `SUM`: Scalar sum of weighted losses.
  - `MEAN`: Scalar `SUM` divided by sum of weights.
  - `SUM_OVER_BATCH_SIZE`: Scalar `SUM` divided by number of elements in losses.
  - `SUM_OVER_NONZERO_WEIGHTS`: Scalar `SUM` divided by number of non-zero
  +
  + * `NONE`: Un-reduced weighted losses with the same shape as input.
  + * `SUM`: Scalar sum of weighted losses.
  + * `MEAN`: Scalar `SUM` divided by sum of weights.
  + * `SUM_OVER_BATCH_SIZE`: Scalar `SUM` divided by number of elements in losses.
  + * `SUM_OVER_NONZERO_WEIGHTS`: Scalar `SUM` divided by number of non-zero
  weights.
  - `SUM_BY_NONZERO_WEIGHTS`: Same as `SUM_OVER_NONZERO_WEIGHTS`.
  + * `SUM_BY_NONZERO_WEIGHTS`: Same as `SUM_OVER_NONZERO_WEIGHTS`.
  """
  NONE = "none"
  