Admin setting to disable default follows (#12566)

app/models/form/admin_settings.rb

@@ -16,6 +16,7 @@ class Form::AdminSettings
     open_deletion
     timeline_preview
     show_staff_badge
+    enable_bootstrap_timeline_accounts
     bootstrap_timeline_accounts
     theme
     min_invite_role
@@ -40,6 +41,7 @@ class Form::AdminSettings
     open_deletion
     timeline_preview
     show_staff_badge
+    enable_bootstrap_timeline_accounts
     activity_api_enabled
     peers_api_enabled
     show_known_fediverse_at_about_page