Update index.rst

Author: ThomasLandauer

src/Icons/doc/index.rst

@@ -526,7 +526,7 @@ TwigComponent
 ~~~~~~~~~~~~~
 
 The ``ux_icon()`` function is optimized to be as fast as possible. To deliver the
-same level of performance as if using the HTML syntax (``<twig:ux:icon name="..." />``),
+same level of performance when using the HTML syntax (``<twig:ux:icon name="..." />``),
 the TwigComponent overhead is reduced by calling the IconRenderer immediately and
 returning the HTML output.