fix: show pointer cursor on theme switcher button hover (#15)

Author: letavocado

src/components/theme-switcher.astro

@@ -6,7 +6,7 @@ import { Icon } from "astro-icon/components";
   negative margin is sum of button width (8) and gap size of flex parent (6)
   TODO don't hardcode these values
 -->
-<button id="theme-switcher" type="button" class="ml-0 origin-(right_center)">
+<button id="theme-switcher" type="button" class="ml-0 origin-(right_center) cursor-pointer">
   <div id="icon-theme-auto">
     <Icon name="tabler:sun-moon" class="h-8 text-lg" />
     <span class="sr-only">Use dark theme</span>