chore: uniformize icons in Button / Input / Select / SelectMenu

Also adds `loading` to `Select` and `SelectMenu`

docs/content/3.forms/4.select-menu.md

@@ -162,10 +162,6 @@ const selected = ref(people[0])
 
 ### Icon
 
-Use any icon from [Iconify](https://icones.js.org) by setting the `icon` prop by using this pattern: `i-{collection_name}-{icon_name}`.
-
-Use the `trailing-icon` prop to set a different icon or change it globally in `ui.select.default.trailingIcon`. Defaults to `i-heroicons-chevron-down-20-solid`.
-
 Use the `selected-icon` prop to set a different icon or change it globally in `ui.selectMenu.default.selectedIcon`. Defaults to `i-heroicons-check-20-solid`.
 
 ::component-card
@@ -175,16 +171,16 @@ baseProps:
   placeholder: 'Select a person'
   options: ['Wade Cooper', 'Arlene Mccoy', 'Devon Webb', 'Tom Cook', 'Tanya Fox', 'Hellen Schmidt', 'Caroline Schultz', 'Mason Heaney', 'Claudie Smitham', 'Emil Schaefer']
 props:
-  icon: 'i-heroicons-magnifying-glass-20-solid'
-  color: 'white'
-extraColors:
-  - white
-  - gray
+  selectedIcon: 'i-heroicons-hand-thumb-up-solid'
 excludedProps:
-  - icon
+  - selectedIcon
 ---
 ::
 
+::alert{icon="i-heroicons-light-bulb"}
+Learn how to customize icons from the [Select](/forms/select#icon) component.
+::
+
 ### Search
 
 Use the `searchable` prop to enable search.