Updated shortcuts

frontend/static/flatpages/keyboard.md

@@ -1,8 +1,8 @@
-- `Cmd+/` - Toggle navigation tree
-- `Cmd+Enter` - Save document
+- `Cmd+Enter` - Save and exit document editor
+- `Cmd+s` - Save document and continue editing
 - `Cmd+Esc` - Cancel edit
-- `Cmd+Shift+p` - Toggle document preview
 - `/` or `t` - Jump to search
 - `d` - Jump to dashboard
 - `c` - Compose within a collection
 - `e` - Edit document
+- `?` - This guide