✨ feat: add search functionality (#250)

i18n/zh-Hans.toml

@@ -14,6 +14,13 @@ privacy = "隐私政策"  # Machine translated.
 site_statistics = "网站统计"  # Machine translated.
 sitemap = "站点地图"  # Machine translated.
 
+# Search.
+search = "搜索"
+search_icon_title = "点击或按 $SHORTCUT 开启搜索"  # $SHORTCUT will be replaced with the actual keyboard shortcut.
+clear_search = "清除搜索"  # Title of the X icon next to search input.
+result = "结果"  # "1 result"
+results = "结果"  # "3 results" (also used for 0 results).
+
 # Navigation.
 read_more = "阅读全文"
 post = "文章"