[core] Enable linting mdx files and fix violations (#1292)

docs/src/app/(public)/(content)/react/components/alert-dialog/page.mdx

@@ -39,7 +39,7 @@ import { AlertDialog } from '@base-ui-components/react/alert-dialog';
 
 In order to open a dialog using a menu, control the dialog state and open it imperatively using the `onClick` handler on the menu item.
 
-Make sure to also use the dialog’s `finalFocus` prop to return focus back to the menu trigger.
+Make sure to also use the dialog's `finalFocus` prop to return focus back to the menu trigger.
 
 ```tsx {12-13,17-18,24-25,28-29} title="Connecting a dialog to a menu"
 import * as React from 'react';

docs/src/app/(public)/(content)/react/components/dialog/page.mdx

@@ -76,7 +76,7 @@ return (
 );
 ```
 
-It’s also common to use `onOpenChange` if your app needs to do something when the dialog is closed or opened. This is recommended over `React.useEffect` when reacting to state changes.
+It's also common to use `onOpenChange` if your app needs to do something when the dialog is closed or opened. This is recommended over `React.useEffect` when reacting to state changes.
 
 ```tsx title="Running code when dialog state changes"
 <Dialog.Root
@@ -96,7 +96,7 @@ It’s also common to use `onOpenChange` if your app needs to do something when
 
 In order to open a dialog using a menu, control the dialog state and open it imperatively using the `onClick` handler on the menu item.
 
-Make sure to also use the dialog’s `finalFocus` prop to return focus back to the menu trigger.
+Make sure to also use the dialog's `finalFocus` prop to return focus back to the menu trigger.
 
 ```tsx {12-13,17-18,24-25,28-29} title="Connecting a dialog to a menu"
 import * as React from 'react';

docs/src/app/(public)/(content)/react/components/menu/page.mdx

@@ -126,7 +126,7 @@ Use the `render` prop to compose a menu item with an anchor element.
 
 In order to open a dialog using a menu, control the dialog state and open it imperatively using the `onClick` handler on the menu item.
 
-Make sure to also use the dialog’s `finalFocus` prop to return focus back to the menu trigger.
+Make sure to also use the dialog's `finalFocus` prop to return focus back to the menu trigger.
 
 ```tsx {12-13,17-18,24-25,28-29} title="Connecting a dialog to a menu"
 import * as React from 'react';

docs/src/app/(public)/(content)/react/handbook/composition/page.mdx

@@ -6,7 +6,7 @@
   content="A guide to composing Base UI components with your own React components."
 />
 
-### Composing custom React components
+## Composing custom React components
 
 Use the `render` prop to compose a Base UI part with your own React components.
 
@@ -22,7 +22,7 @@ The code snippet below shows how to use a custom button instead.
 
 The custom component must forward the `ref`, and spread all the received props on its underlying DOM node.
 
-### Composing multiple components
+## Composing multiple components
 
 In situations where you need to compose multiple Base UI components with custom React components, `render` props can be nested as deeply as necessary.
 Working with Tooltip is a common example.
@@ -48,7 +48,7 @@ Working with Tooltip is a common example.
 </Dialog.Root>
 ```
 
-### Changing the default rendered element
+## Changing the default rendered element
 
 You can also use the `render` prop to override the rendered element of the component.
 
@@ -78,7 +78,7 @@ export default () => (
 
 Each Base UI component renders the most appropriate element by default, and in most cases, rendering a different element is recommended only on a case-by-case basis.
 
-### Render function
+## Render function
 
 If you are working in an extremely performance-sensitive application, you might want to pass a function to the `render` prop instead of a React element.
 

package.json

@@ -27,7 +27,7 @@
     "eslint": "eslint . --cache --report-unused-disable-directives --ext .js,.ts,.tsx --max-warnings 0",
     "eslint:ci": "eslint . --report-unused-disable-directives --ext .js,.ts,.tsx --max-warnings 0",
     "stylelint": "stylelint --reportInvalidScopeDisables --reportNeedlessDisables \"docs/**/*.{js,ts,tsx}\" --ignore-path .gitignore",
-    "markdownlint": "markdownlint-cli2 \"**/*.md\"",
+    "markdownlint": "markdownlint-cli2 \"**/*.{md,mdx}\"",
     "prettier": "pretty-quick --ignore-path .eslintignore",
     "prettier:all": "prettier --write . --ignore-path .eslintignore",
     "size:snapshot": "node --max-old-space-size=4096 ./scripts/sizeSnapshot/create",