I couldn’t find any plasmoid that lets you add a basic text file to the desktop,
is it possible?
right click on the desktop, create new, text file
do you have your desktop set to folder view?
I didn’t explain it well,
not put an actual file in the desktop folder, but display an .md file inside a widget
The Sticky Notes widget is more or less intended for this use case, though it doesn’t render markdown formatting or allow you to choose the data source to be a file of your choosing.
there is a widget for displaying a webpage on the desktop but i just tied adding it to my desktop and it crashed plasma 6.1
i’d file a bug report but 6.1 is not supported… only 5.27 and 6.2