feat: new archives layout (#989)

* feat(archives): add search bar to archives page

* fix: error `file is nil; wrap it in if or with` from Hugo 0.123.0

* style: rename `search.ts` to `archives.ts`

* refactor: remove `search` page layout

* doc: remove `search` from `exampleSite`

* fix: generate JSON output for archives page in exampleSite

* feat: put archives search form under categories list

layouts/partials/widget/search.html

@@ -1,4 +1,4 @@
-{{- $query := first 1 (where .Context.Site.Pages "Layout" "==" "search") -}}
+{{- $query := first 1 (where .Context.Site.Pages "Layout" "==" "archives") -}}
 {{- if $query -}}
     {{- $searchPage := index $query 0 -}}
     <form action="{{ $searchPage.RelPermalink }}" class="search-form widget" {{ with .OutputFormats.Get "json" -}}data-json="{{ .Permalink }}" {{- end }}>
@@ -12,5 +12,5 @@
         </p>
     </form>
 {{- else -}}
-    {{- warnf "Search page not found. Create a page with layout: search." -}}
+    {{- warnf "Archives page not found. Create a page with layout: archives." -}}
 {{- end -}}