pythongh-100556: Improve clarity of or docs (python#100589)

Co-authored-by: Hugo van Kemenade <hugovk@users.noreply.github.com>

Doc/library/stdtypes.rst

@@ -84,8 +84,8 @@ These are the Boolean operations, ordered by ascending priority:
 +-------------+---------------------------------+-------+
 | Operation   | Result                          | Notes |
 +=============+=================================+=======+
-| ``x or y``  | if *x* is false, then *y*, else | \(1)  |
-|             | *x*                             |       |
+| ``x or y``  | if *x* is true, then *x*, else  | \(1)  |
+|             | *y*                             |       |
 +-------------+---------------------------------+-------+
 | ``x and y`` | if *x* is false, then *x*, else | \(2)  |
 |             | *y*                             |       |