Use dark: utilities for DocSearch key styles

Merge the separate [data-theme="dark"] rule into the main .DocSearch-Button-Key selector by using Tailwind's dark: utilities. This consolidates light and dark styles into one rule and changes the dark background from bg-olive-700 to bg-gray-700 for consistency.

Author: Deven14125

src/styles/tailwind.css

@@ -48,10 +48,7 @@
   @apply hidden! lg:flex!;
 }
 .DocSearch-Button-Key {
-  @apply text-gray-700! bg-gray-100! border-gray-300!;
-}
-[data-theme="dark"] .DocSearch-Button-Key {
-  @apply text-gray-100! bg-olive-700! border-gray-500!;
+  @apply text-gray-700! bg-gray-100! border-gray-300! dark:text-gray-100! dark:bg-gray-700! dark:border-gray-500!;
 }
 .DocSearch-Button .DocSearch-Search-Icon {
   @apply text-white! lg:text-gray-100!;