Fix description of move_to_element_with_offset (#11402)

Fix the function comments according to the w3c spec:

https://w3c.github.io/webdriver/#dfn-dispatch-a-pointermove-action

Fixes #10261

Author: j3soon

py/selenium/webdriver/common/action_chains.py

@@ -236,12 +236,12 @@ def move_to_element(self, to_element):
 
     def move_to_element_with_offset(self, to_element, xoffset, yoffset):
         """Move the mouse by an offset of the specified element. Offsets are
-        relative to the top-left corner of the element.
+        relative to the in-view center point of the element.
 
         :Args:
          - to_element: The WebElement to move to.
-         - xoffset: X offset to move to.
-         - yoffset: Y offset to move to.
+         - xoffset: X offset to move to, as a positive or negative integer.
+         - yoffset: Y offset to move to, as a positive or negative integer.
         """
 
         self.w3c_actions.pointer_action.move_to(to_element, int(xoffset), int(yoffset))