Update README.md

Co-authored-by: Sebastian Silbermann <[email protected]>

Author: gnapse

README.md

@@ -533,7 +533,7 @@ expect(getByTestId('parent')).toContainHTML('</span>')
 toHaveAccessibleDescription(expectedAccessibleDescription?: string | RegExp)
 ```
 
-This allows to assert that an element is has the expected
+This allows to assert that an element has the expected
 [accessible description](https://w3c.github.io/accname/).
 
 You can pass the exact string of the expected accessible description, or you can