fix: inline DocSearch CSS for production build compatibility

- Inline docsearch.css into main.css to fix @apply directives not
  processing in production builds
- Fix DocSearch button styling (flex, padding, margins)
- Hide text on Cancel and Reset buttons
- Change search placeholder to "Search"

Author: justin-schroeder

docs/app.vue

@@ -9,6 +9,7 @@ onMounted(async () => {
     apiKey: "57bf4858266f8e7c7037df759ac8df2f",
     maxResultsPerGroup: 4,
     disableUserPersonalization: true,
+    placeholder: "Search",
   })
   document.addEventListener("click", (e) => {
     if (