Docs: Affine - improve fit_output documentation (#1159)

* Rewritten the description of `fit_output` argument for affine transformation.

* minor edit

* Fix flake8

Co-authored-by: Mikhail Druzhinin <dipetm@gmail.com>

albumentations/augmentations/geometric/transforms.py

@@ -469,12 +469,11 @@ class Affine(DualTransform):
             The value is only used when `mode=constant`. The expected value range is ``[0, 255]`` for ``uint8`` images.
         cval_mask (number or tuple of number): Same as cval but only for masks.
         mode (int): OpenCV border flag.
-        fit_output (bool): Whether to modify the affine transformation so that the whole output image is always
-            contained in the image plane (``True``) or accept parts of the image being outside
-            the image plane (``False``). This can be thought of as first applying the affine transformation
-            and then applying a second transformation to "zoom in" on the new image so that it fits the image plane,
-            This is useful to avoid corners of the image being outside of the image plane after applying rotations.
-            It will however negate translation and scaling.
+        fit_output (bool): If True, the image plane size and position will be adjusted to tightly capture
+            the whole image after affine transformation (`translate_percent` and `translate_px` are ignored).
+            Otherwise (``False``),  parts of the transformed image may end up outside the image plane.
+            Fitting the output shape can be useful to avoid corners of the image being outside the image plane
+            after applying rotations. Default: False
         keep_ratio (bool): When True, the original aspect ratio will be kept when the random scale is applied.
                            Default: False.
         p (float): probability of applying the transform. Default: 0.5.