Add homepage posts endpoint

app/controllers/api/v1/posts_controller.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+class Api::V1::PostsController < ApplicationController
+  def latest
+    @posts = Post.published.last(3)
+  end
+end

app/views/api/v1/posts/latest.json.jbuilder

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+json.array! @posts do |post|
+  json.title post.title
+  json.article_type post.article_type
+  json.summary post.summary
+  json.slug post.slug
+  json.created_at post.created_at
+end

config/routes.rb

@@ -49,6 +49,9 @@
       resources :stores do
         get "random", to: "stores#random", on: :collection
       end
+      resources :posts do
+        get "latest", to: "posts#latest", on: :collection
+      end
     end
   end