Improved wording.

Doc/library/string.rst

@@ -434,10 +434,10 @@ The available presentation types for floating point and decimal values are:
    | ``'%'`` | Percentage. Multiplies the number by 100 and displays    |
    |         | in fixed (``'f'``) format, followed by a percent sign.   |
    +---------+----------------------------------------------------------+
-   | None    | Similar to ``'g'``, except with at least one decimal     |
-   |         | point and a default precision of 12. This is intended to |
-   |         | match :func:`str`, except you can add the other          |
-   |         | format modifiers.                                        |
+   | None    | Similar to ``'g'``, except with at least one digit past  |
+   |         | the decimal point and a default precision of 12. This is |
+   |         | intended to match :func:`str`, except you can add the    |
+   |         | other format modifiers.                                  |
    +---------+----------------------------------------------------------+