Add cold-start follow recommendations (#15945)

db/migrate/20210324171613_create_follow_recommendation_suppressions.rb

@@ -0,0 +1,9 @@
+class CreateFollowRecommendationSuppressions < ActiveRecord::Migration[6.1]
+  def change
+    create_table :follow_recommendation_suppressions do |t|
+      t.references :account, null: false, foreign_key: { on_delete: :cascade }, index: { unique: true }
+
+      t.timestamps
+    end
+  end
+end