Add and apply rules for multi-line arrays

We were already applying these rules in most cases.

Note we aren't enabling the `MultilineArrayLineBreaks` rule because
we've got places with many elements whire it isn't clear whether
having one element per line would make the code more readable.

spec/lib/tasks/seed_spec.rb

@@ -5,8 +5,8 @@ describe "rake db:seed" do
     default_locales = I18n.available_locales
     begin
       I18n.available_locales = [:ar, :bg, :bs, :ca, :cs, :da, :de, :el, :en, :es, :"es-PE", :eu, :fa, :fr,
-        :gl, :he, :hr, :id, :it, :ka, :nl, :oc, :pl, :"pt-BR",
-        :ro, :ru, :sl, :sq, :so, :sr, :sv, :tr, :val, :"zh-CN", :"zh-TW"]
+                                :gl, :he, :hr, :id, :it, :ka, :nl, :oc, :pl, :"pt-BR",
+                                :ro, :ru, :sl, :sq, :so, :sr, :sv, :tr, :val, :"zh-CN", :"zh-TW"]
       SiteCustomization::Page.destroy_all
       load Rails.root.join("db", "pages.rb")