WIP

Things to figure out:

- Why is isso breaking when I add the modal (TODO: try individual
  components and see if that still breaks Isso; just to investigate)
- Can we use the modal trigger but have that just go to a custom page,
  or should it just build the search menu at the top of the current page
  (not an overlay like the all-in-one searchbox you can add; I mean
  actually it just goes to the top of the body and puts the search menu
  and filtering stuff there)
- Dark mode

layouts/_partials/top.html

@@ -5,6 +5,9 @@
         </a>
     </div>
 
+    <pagefind-modal-trigger></pagefind-modal-trigger>
+    <pagefind-modal></pagefind-modal>
+
     <nav class="top-navbar" aria-label="{{ i18n "aria_navbar" }}">
         {{ with .Site.Home }}
             <a class="top-navbar-item{{ if $.IsHome }} top-navbar-item--active{{ end }}" href="{{ .Permalink | absLangURL }}">{{ .Title | markdownify }}</a>