Enable use of Action Caching in the API 🎉

See: https://guides.rubyonrails.org/api_app.html#adding-other-modules

app/models/concerns/api_action_caching.rb

@@ -0,0 +1,20 @@
+# frozen_string_literal: true
+
+# API controllers inherit from ActionController::Metal to keep them slim and fast.
+# This concern adds the minimum requirements needed to use Action Caching in the API.
+
+module ApiActionCaching
+  extend ActiveSupport::Concern
+
+  included do
+    include ActionController::Caching
+    include ActionController::Caching::Actions
+    include AbstractController::Layouts
+
+    # This config is not passed to the controller automatically with ActionController::Metal
+    self.cache_store = Rails.configuration.cache_store
+
+    # ActionController::Caching asks for a controller's layout, but they're not used in the API
+    layout false
+  end
+end