menu/prompt indicator not rendered if it starts with a newline

[maxomatic458]

Platform windows 10 Terminal software windows terminal

when the menu marker starts with a "\n", then the characters after that will not be shown on screen.

1. so the following marker marker: "\nMARKER " will be rendered as \n
2. when adding a space (or any character) in front of the marker, for example marker: " \nMARKER ", it will be fixed

Steps to reproduce

1. make the marker of a menu start with "\n", and then trigger a completion

Screenshots/Screencaptures

1. "\nMARKER "
2. " \nMARKER "

i think its happening in this function https://github.com/nushell/reedline/blob/31eaeeb231664b889c92595ff38ead4ccb570766/src/painting/utils.rs#L8

see #696 for more info