Add the search action for Books.

lib/decentralised_book_index/metadata/book.ex

@@ -101,6 +101,17 @@ defmodule DecentralisedBookIndex.Metadata.Book do
       end
     end
 
+    read :search do
+      argument :query, :ci_string do
+        constraints allow_empty?: true
+        default ""
+      end
+
+      filter expr(contains(title, ^arg(:query)))
+
+      pagination offset?: true, default_limit: 10
+    end
+
     update :assign_cover_image do
       accept [:cover_image_url]
     end