Editora 0.9.10. Archived, so links from that release keep working. Read the 0.18.5 page →
Markdown: Toggle Format Bar
markdown.toggleFormatBar Turn the Markdown selection format bar on or off.
How to run it
Open the command palette (M-x in the Emacs keymap) and search for Markdown: Toggle Format Bar, then press Enter. It has no default keybinding, but you can bind one in Settings → Keymaps.