Add highlights

app/relations/highlights.rb

@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+module Adamantium
+  module Relations
+    class Highlights < ROM::Relation[:sql]
+      schema :highlights, infer: true do
+        associations do
+          belongs_to :post
+        end
+      end
+
+      auto_struct(true)
+    end
+  end
+end