hyprland-wiki: `s/windowrule/windowrulev2`

* Replace references to 'windowrule' in the paragraph "Window Rules V2"
  with 'windowrulev2' instead. Clears doubts as seen in hyprwm/Hyprland#874.

* Also fix the syntax for the various examples. Maybe someone should stop
  drinking beer?
   - ^(kitty)$, ^(firefox)$ -> class:^(kitty)$, class^(firefox)$

pages/Configuring/Window-Rules.md

@@ -74,9 +74,9 @@ Keep in mind you do *not* need to define all of them, but you need to define at
 
 *Examples*:
 ```ini
-windowrule = move 100 100,^(kitty)$
-windowrule = animation popin,^(kitty)$
-windowrule = noblur,^(firefox)$
+windowrulev2 = move 100 100,class:^(kitty)$
+windowrulev2 = animation popin,class:^(kitty)$
+windowrulev2 = noblur,class:^(firefox)$
 ```
 
 {{< hint type=tip >}}