Where to put a personnalized copy of a layout from layout_discovery? I want to personnalised core/modules/layout_discovery/layouts/twocol/layout--twocol making a copy of it renamed with a suggested name in the display mode but I don't know where to put it in my subtheme of Bootstrap... I've tried different places, but none worked...

Any help will be appreciated.

Drupal 8.4.3.
I putted my layout in drupal\themes\mytheme\layouts\twocol\layout--twocol--node-end-of-a-suggested-name.html.twig and declare it in a mytheme.layouts.yml file at the root of my theme and it worked.