docs: [popover] modify the default value of trigger (element-plus#12342)

docs: update popover.md

Author: XSUV

docs/en-US/component/popover.md

@@ -72,7 +72,7 @@ popover/directive-usage
 
 | Name                      | Description                                                                                                                                                              | Type            | Accepted Values                                                                                           | Default                                                                    |
 | ------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | --------------- | --------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------- |
-| trigger                   | how the popover is triggered                                                                                                                                             | string          | click/focus/hover/contextmenu                                                                             | click                                                                      |
+| trigger                   | how the popover is triggered                                                                                                                                             | string          | click/focus/hover/contextmenu                                                                             | hover                                                                      |
 | title                     | popover title                                                                                                                                                            | string          | —                                                                                                         | —                                                                          |
 | effect                    | Tooltip theme, built-in theme: `dark` / `light`                                                                                                                          | string          | string                                                                                                    | light                                                                      |
 | content                   | popover content, can be replaced with a default `slot`                                                                                                                   | string          | —                                                                                                         | —                                                                          |