Improved docstring of WindowAlign.

Author: jonathanslenders

prompt_toolkit/layout/containers.py

@@ -1146,7 +1146,13 @@ def __init__(self, position, style='class:color-column'):
 
 
 class WindowAlign:
- " Alignment of Window content. "
+ """
+ Alignment of the Window content.
+
+ Note that this is different from `HorizontalAlign` and `VerticalAlign`,
+ which are used for the alignment of the child containers in respectively
+ `VSplit` and `HSplit`.
+ """
  LEFT = 'LEFT'
  RIGHT = 'RIGHT'
  CENTER = 'CENTER'