Is there a text editor with indentation for the first line of a paragraph and spacing between paragraphs?

Question

Text editors

Good afternoon.
I'm trying to find an editor (free, preferably cross-platform) or some extension with the following functionality. When opening any text file, the text would be displayed with a red line and some spacing between paragraphs. That is, the red line would be only when working in the editor, and there would be no tabs or spaces in the file.
If anyone knows at least the direction where to dig, tell me, please.