Fix minor typo in round docs. Reported by Scott Hinton on docs@.

Doc/library/functions.rst

@@ -1229,7 +1229,7 @@ available.  They are listed here in alphabetical order.
    the decimal point.  If *ndigits* is omitted, it defaults to zero. The result
    is a floating point number.  Values are rounded to the closest multiple of
    10 to the power minus *ndigits*; if two multiples are equally close,
-   rounding is done away from 0 (so. for example, ``round(0.5)`` is ``1.0`` and
+   rounding is done away from 0 (so, for example, ``round(0.5)`` is ``1.0`` and
    ``round(-0.5)`` is ``-1.0``).