Update Doc/using/configure.rst

Co-authored-by: Hugo van Kemenade <[email protected]>

Author: vstinner

Doc/using/configure.rst

@@ -294,7 +294,7 @@ General Options
    Enables **experimental** support for running Python without the
    :term:`global interpreter lock` (GIL): free threading build.
 
-   Define the ``Py_GIL_DISABLED`` macro and add ``"t"`` to
+   Defines the ``Py_GIL_DISABLED`` macro and adds ``"t"`` to
    :data:`sys.abiflags`.
 
    See :pep:`703` "Making the Global Interpreter Lock Optional in CPython".