Rephrase and fix indentation

Co-authored-by: Savannah Ostrowski <savannah@python.org>

Author: ptim0626

Doc/library/argparse.rst

@@ -1624,10 +1624,10 @@ argument::
 See also :ref:`the argparse howto on ambiguous arguments <specifying-ambiguous-arguments>`
 for more details.
 
-   .. versionchanged:: 3.14
-      Negative numbers in scientific notation (``-2.5e-6``), with underscores
-      (``-1_234.5``) and complex numbers (``-1.2e-3j``) are recognized as
-      negative numbers.
+.. versionchanged:: 3.14
+   Negative-number matching was expanded to include numbers in scientific
+   notation (``-2.5e-6``), numbers containing underscores (``-1_234.5``),
+   and complex numbers (``-1.2e-3j``).
 
 .. _prefix-matching: