With thanks for the guidance of @matchavez, the Shortcut below adds a bullet-point date-and-text entry to a specified file in a specified folder, both of which need to be personalized by editing the Shortcut to point the the user’s vault > subfolder > file name. It also adds a commented date-and-time entry at the end of each line (which I need in my vault if I ever want to look back and see when the line was created).
On macOS, it can be added to the dock, menu bar, and Share Sheet, and given a keyboard shortcut. Obsidian does not need to be running for it to work.
On iOS, it can be added to the Home Screen and Share Sheet. Again, Obsidian does not need to be running for it to work.
Obsidian Shortcuts Note.zip (12.4 KB)