v2 Suggestions: add index on is_suggested column

priv/repo/migrations/20211126191138_add_suggestions.exs

@@ -5,5 +5,7 @@ def change do
     alter table(:users) do
       add(:is_suggested, :boolean, default: false, null: false)
     end
+
+    create_if_not_exists(index(:users, [:is_suggested]))
   end
 end