mark, so that it’s no longer located anywhere in the buffer.
Removes the reference the buffer holds to the mark, so if you haven’t called
@ref on the mark, it will be freed. Even if the mark isn’t freed, most operations on
mark become invalid, until it gets
added to a buffer again with add_mark. Use
get_deleted to find out if a mark has been removed from its buffer. The
mark_deleted signal will be emitted as notification after the mark is
a TextMark in this