chore: Add articles metadata (#5125)

app/views/api/v1/accounts/articles/index.json.jbuilder

@@ -1,3 +1,8 @@
 json.payload do
   json.array! @articles, partial: 'article', as: :article
 end
+
+json.meta do
+  json.current_page @current_page
+  json.articles_count @articles.size
+end