Editora 0.9.10. Archived, so links from that release keep working. Read the 0.18.5 page →
Local History: Put Label…
history.putLabel Record a named snapshot of the current file in Local History.
How to run it
Open the command palette (M-x in the Emacs keymap) and search for Local History: Put Label…, then press Enter. It has no default keybinding, but you can bind one in Settings → Keymaps.