Added language and theme settings.

components/settings/ThemeSetting.js

@@ -0,0 +1,25 @@
+import classNames from 'classnames';
+import Button from 'components/common/Button';
+import useTheme from 'hooks/useTheme';
+import Sun from 'assets/sun.svg';
+import Moon from 'assets/moon.svg';
+import styles from './ThemeSetting.module.css';
+
+export default function ThemeSetting() {
+  const [theme, setTheme] = useTheme();
+
+  return (
+    <div className={styles.buttons}>
+      <Button
+        className={classNames({ [styles.active]: theme === 'light' })}
+        icon={<Sun />}
+        onClick={() => setTheme('light')}
+      />
+      <Button
+        className={classNames({ [styles.active]: theme === 'dark' })}
+        icon={<Moon />}
+        onClick={() => setTheme('dark')}
+      />
+    </div>
+  );
+}