chore(v2): turn off import/extensions ESLint rule

.eslintrc.js

@@ -30,6 +30,7 @@ module.exports = {
       ERROR,
       {ignore: ['^@theme', '^@docusaurus', '^@generated']},
     ],
+    'import/extensions': OFF,
     'header/header': [
       ERROR,
       'block',

packages/docusaurus-theme-classic/src/theme/hooks/useHideableNavbar.js

@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import React, {useState, useCallback, useEffect} from 'react'; // eslint-disable-line no-unused-vars
+import {useState, useCallback, useEffect} from 'react';
 
 const useHideableNavbar = hideOnScroll => {
   const [isNavbarVisible, setIsNavbarVisible] = useState(true);

packages/docusaurus-theme-classic/src/theme/hooks/useTheme.js

@@ -4,6 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  */
+
 import * as React from 'react';
 
 const useTheme = () => {