Although the RandomScale and ShiftScaleRotate use the same sampling strategy, it is explained differently.

See:

• RandomScale
  "If scale_limit is a single float value, the range will be (1 - scale_limit, 1 + scale_limit). Default: (0.9, 1.1)"

• ShiftScaleRotate
  "If scale_limit is a single float value, the range will be (-scale_limit, scale_limit). Default: (-0.1, 0.1)."

I think the ShiftScaleRotate's doc is better because saying that default is (0.9, 1.1) is misleading.

And to mitigate confusion about RandomScale (#910 #568 #548 #737), I add the following sentences.

"Note that the scale_limit will be biased by 1. When the scale_limit is a tuple, like (low, high), sampling will be done from the range (1 + low, 1 + high)."

I appreciate it if you review this.