theme notes refer to core_maintenance_renderer not core_renderer_maintenance

This file:

https://github.com/moodle/moodle/blob/master/theme/upgrade.txt

has several references to core_maintenance_renderer:

• core_maintenance_renderer::block
• core_maintenance_renderer::blocks
• core_maintenance_renderer::blocks_for_regions
• core_maintenance_renderer::course_header
• core_maintenance_renderer::course_footer
• core_maintenance_renderer::course_content_header
• core_maintenance_renderer::course_content_footer
• core_maintenance_renderer::custom_menu
• core_maintenance_renderer::file_picker
• core_maintenance_renderer::htmllize_file_tree
• core_maintenance_renderer::lang_menu
• core_maintenance_renderer::login_info
• core_maintenance_renderer::user_picture

but it's actually core_renderer_maintenance, which confused me when I was searching for it.