A menu item is meant to be used to trigger an action. For a button that
toggles the visibility of a menu, use menu_button/1.
Usage
<.menu label="Actions">
<:item>
<.menu_item on_click={JS.dispatch("myapp:copy")}>
Copy
</.menu_item>
</:item>
<:item>
<.menu_item on_click={JS.dispatch("myapp:paste")}>
Paste
</.menu_item>
</:item>
</.menu>