add something in tutorial.lyx

Dear Uwe and Lyx-docs team
thank you for all.

sugg:
i hope you add the red text in tutorail.lyx (3.5 footnotes and margin
notes):
Margin notes are like footnotes, except that:


   - the on-screen boxes say “margin” instead of “foot”


   - the notes will be placed in the margin, instead of below the text
   - margin notes are not numbered, but can numbered with samll latex code
   (
   \captionof[figure]{}or\captionof[table]{}).
   - margin note can containt table or image.

best regards