Adjust DocSearch button dark theme colors

Refine dark-mode styles for .DocSearch-Button-Key in tailwind.css: change dark:text to gray-900, dark:bg to gray-200, and dark:border to gray-400 to improve contrast and better match the site's dark theme.

Author: Deven14125

src/styles/tailwind.css

@@ -48,7 +48,7 @@
   @apply hidden! lg:flex!;
 }
 .DocSearch-Button-Key {
-  @apply text-gray-700! bg-gray-100! border-gray-300! dark:text-gray-100! dark:bg-blue-400! dark:border-gray-500!;
+  @apply text-gray-700! bg-gray-100! border-gray-300! dark:text-gray-900! dark:bg-gray-200! dark:border-gray-400!;
 }
 .DocSearch-Button .DocSearch-Search-Icon {
   @apply text-white! lg:text-gray-100!;