Ask HN: IDE that provides text formatting

This is kind of a weird use case for an IDE, but does anyone know of a good IDE (or editor) for taking notes? All my files will be text files, and I want the ability to format text (e.g. change font size, underline or emphasize text, etc.), but would like to use an IDE or code editor because they provide really useful features (like hotkeys for searching through files or searching file names, which is really important to me for quick navigation). Any ideas or suggestions? The current hack I use is using more text to add visual emphasis (like a row of "=" to delineate sections in my notes).