[docs] Move SelectUnstyled docs to the Base space (#31816)

Co-authored-by: Sam Sycamore <71297412+samuelsycamore@users.noreply.github.com>
Co-authored-by: Siriwat K <siriwatkunaporn@gmail.com>
Co-authored-by: Marija Najdova <mnajdova@gmail.com>

docs/data/base/components/select/select.md

@@ -0,0 +1,105 @@
+---
+product: base
+title: React Select unstyled component and hook
+components: SelectUnstyled, MultiSelectUnstyled, OptionUnstyled, OptionGroupUnstyled
+githubLabel: 'component: select'
+waiAria: https://www.w3.org/TR/wai-aria-practices/#combobox
+packageName: '@mui/base'
+---
+
+# Unstyled select
+
+<p class="description">The select components let you create lists of options for users to choose from.</p>
+
+{{"component": "modules/components/ComponentLinkHeader.js", "design": false}}
+
+MUI Base offers two components to replace the native HTML `<select>` tag: `SelectUnstyled` and `MultiSelectUnstyled`.
+
+## SelectUnstyled
+
+```tsx
+import SelectUnstyled from '@mui/base/SelectUnstyled';
+```
+
+### Basic select
+
+{{"demo": "UnstyledSelectSimple.js", "defaultCodeOpen": false}}
+
+The `SelectUnstyled` component accepts generic props.
+Due to TypeScript limitations, this may cause unexpected behavior when wrapping the component in `forwardRef` (or other higher-order components).
+In such cases, the generic argument will be defaulted to `unknown` and type suggestions will be incomplete.
+To avoid this, you can manually cast the resulting component to the correct type:
+
+```tsx
+const CustomSelect = React.forwardRef(function CustomSelect<TValue>(
+  props: SelectUnstyledProps<TValue>,
+  ref: React.ForwardedRef<HTMLUListElement>,
+) {
+  // ...your code here...
+  return <SelectUnstyled {...props} ref={ref} />;
+}) as <TValue>(
+  props: SelectUnstyledProps<TValue> & React.RefAttributes<HTMLUListElement>,
+) => JSX.Element;
+```
+
+For the sake of brevity, the rest of the demos that follow will not use `forwardRef`.
+
+### Controlled select
+
+`SelectUnstyled` can be used as an uncontrolled (as shown in the demo above) or controlled component.
+
+{{"demo": "UnstyledSelectControlled.js", "defaultCodeOpen": false}}
+
+### Object values
+
+The `SelectUnstyled` component can be used with non-string values.
+
+{{"demo": "UnstyledSelectObjectValues.js", "defaultCodeOpen": false}}
+
+### Selected value appearance
+
+You can customize the selected value display by providing a function to the `renderValue` prop.
+The element returned by this function will be rendered inside the select's button.
+
+{{"demo": "UnstyledSelectCustomRenderValue.js", "defaultCodeOpen": false}}
+
+### Option appearance
+
+Options don't have to be plain strings.
+You can include custom elements to be rendered inside the listbox.
+
+{{"demo": "UnstyledSelectRichOptions.js", "defaultCodeOpen": false}}
+
+### Grouping options
+
+Options can be grouped, similarly to the how the native `select` element works.
+Unlike the native `select`, however, groups can be nested.
+
+Place the `Option` components inside `OptionGroup` to achieve this.
+
+{{"demo": "UnstyledSelectGrouping.js", "defaultCodeOpen": false}}
+
+## MultiSelectUnstyled
+
+The `MultiSelectUnstyled` component lets your users select multiple options.
+
+```js
+import { MultiSelectUnstyled } from '@mui/base/SelectUnstyled';
+```
+
+{{"demo": "UnstyledSelectMultiple.js", "defaultCodeOpen": false}}
+
+## The useSelect hook
+
+```js
+import { useSelect } from '@mui/base/SelectUnstyled';
+```
+
+You can use the `useSelect` hook to apply the functionality of the unstyled select components to a different component.
+This hook gives you the most customization options, but requires more work to implement.
+Using the hook allows you to take full control over the rendered components, their props and CSS classes.
+
+The following example shows a select that opens when hovered over or focused.
+It can be controlled by a mouse/touch or a keyboard.
+
+{{"demo": "UseSelect.js", "defaultCodeOpen": false}}

docs/data/base/pages.ts

@@ -17,6 +17,7 @@ const pages = [
         children: [
           { pathname: '/base/react-button', title: 'Button' },
           { pathname: '/base/react-input', title: 'Input' },
+          { pathname: '/base/react-select', title: 'Select' },
         ],
       },
       {

docs/data/material/components/selects/selects.md

@@ -1,8 +1,9 @@
 ---
 product: material-ui
 title: React Select component
-components: Select, NativeSelect, SelectUnstyled, MultiSelectUnstyled, OptionUnstyled, OptionGroupUnstyled
+components: Select, NativeSelect
 githubLabel: 'component: select'
+unstyled: /base/react-select/
 ---
 
 # Select
@@ -150,84 +151,3 @@ For a [native select](#native-select), you should mention a label by giving the
   <option value="20">Twenty</option>
 </NativeSelect>
 ```
-
-## Unstyled
-
-The Select also comes with an unstyled version.
-It's ideal for doing heavy customizations and minimizing bundle size.
-
-### Unstyled component
-
-```jsx
-import SelectUnstyled from '@mui/base/SelectUnstyled';
-```
-
-#### Basic usage
-
-{{"demo": "UnstyledSelectSimple.js"}}
-
-The `SelectUnstyled` is a component that accepts generic props.
-Due to Typescript limitations, this may cause unexpected behavior when wrapping the component in `forwardRef` (or other higher-order components).
-In such cases, the generic argument will be defaulted to `unknown` and type suggestions will be incomplete.
-To avoid this, manually cast the resulting component to the correct type (as shown above).
-
-The rest of the demos below will not use `forwardRef` for brevity.
-
-#### Controlled select
-
-The SelectUnstyled can be used as either uncontrolled (as shown in the demo above) or controlled component.
-
-{{"demo": "UnstyledSelectControlled.js"}}
-
-#### Usage with object values
-
-The unstyled select may be used with non-string values.
-
-{{"demo": "UnstyledSelectObjectValues.js"}}
-
-#### Customizing the selected value appearance
-
-It is possible to customize the selected value display by providing a function to the `renderValue` prop.
-The element returned by this function will be rendered inside the select's button.
-
-{{"demo": "UnstyledSelectCustomRenderValue.js"}}
-
-#### Customizing the options' appearance
-
-Options don't have to be plain strings.
-You can include custom elements to be rendered inside the listbox.
-
-{{"demo": "UnstyledSelectRichOptions.js"}}
-
-#### Grouping
-
-Options can be grouped, similarly to the how the native `select` element works.
-Unlike the native `select`, however, the groups can be nested.
-
-Place the `Option` components inside `OptionGroup` to achieve this.
-
-{{"demo": "UnstyledSelectGrouping.js"}}
-
-#### Multiselect
-
-To be able to select multiple options at once, use the `MultiSelectUnstyled` component.
-
-```js
-import { MultiSelectUnstyled } from '@mui/base/SelectUnstyled';
-```
-
-{{"demo": "UnstyledSelectMultiple.js"}}
-
-### useSelect hook
-
-```js
-import { useSelect } from '@mui/base/SelectUnstyled';
-```
-
-If you need to use Select's functionality in another component, you can use the `useSelect` hook.
-It enables maximal customizability at the cost of being low-level.
-
-The following example shows a select that opens when hovered over or focused.
-It can be controlled by a mouse/touch or a keyboard.
-
-{{"demo": "UseSelect.js"}}