Add cold-start follow recommendations (#15945)

config/routes.rb

@@ -292,6 +292,7 @@ Rails.application.routes.draw do
     end
 
     resources :account_moderation_notes, only: [:create, :destroy]
+    resource :follow_recommendations, only: [:show, :update]
 
     resources :tags, only: [:index, :show, :update] do
       collection do
@@ -507,6 +508,7 @@ Rails.application.routes.draw do
     namespace :v2 do
       resources :media, only: [:create]
       get '/search', to: 'search#index', as: :search
+      resources :suggestions, only: [:index]
     end
 
     namespace :web do