refactor: added types to SideNavFooter (#14863)

* refactor: mrigrate to ts

* fix: added description for each prop

---------

Co-authored-by: TJ Egan <[email protected]>

packages/react/src/components/UIShell/SideNavFooter.js → packages/react/src/components/UIShell/SideNavFooter.tsx

@@ -12,6 +12,27 @@ import React from 'react';
 import PropTypes from 'prop-types';
 import { usePrefix } from '../../internal/usePrefix';
 
+export interface SideNavFooterProps {
+  /**
+   * Provide text to be read to screen readers and shown as a tooltip when
+   * interacting with the toggle button in the footer
+   */
+  assistiveText: string;
+
+  className?: string;
+
+  /**
+   * Specify whether the side navigation is expanded or collapsed
+   */
+  expanded: boolean;
+
+  /**
+   * Provide a function that is called when the toggle button is interacted
+   * with. Useful for controlling the expansion state of the side navigation.
+   */
+  onToggle: (event: React.MouseEvent<HTMLButtonElement>) => void;
+}
+
 /**
  * SideNavFooter is used for rendering the button at the bottom of the side
  * navigation that is a part of the UI Shell. It is responsible for handling the
@@ -22,7 +43,7 @@ function SideNavFooter({
   className: customClassName,
   expanded,
   onToggle,
-}) {
+}: SideNavFooterProps) {
   const prefix = usePrefix();
   const className = cx(`${prefix}--side-nav__footer`, customClassName);
   return (