cursor.go
func (c *Cursor) Move(shift int) {
	// delete the current cursor
	c.Position = c.Position + shift
	c.correctPosition()
}
func (c *Cursor) Move(shift int) {
	// delete the current cursor
	c.Position = c.Position + shift
	c.correctPosition()
}
// Move moves the cursor over in relative terms, by shift indices.