Adds the ability to group notes. Works the same as "name", but should use "group" instead. For it to work, you need to pre-write all the notes of the name, and then assign them separately. Example: <ref group = "1, 2, 3, 4, 5" />. To open them, click on the group of notes, and then a window will open with a list of specified notes. The number of notes will be displayed in the window, another window with information will be opened when hovering (combination with ReferencePopups), and when you click, it will redirect to the notes (note section, or where the last <references/> are located).