The scarf is a shallow triangle knitted from end to end.
The i-cord edge and lace border are both knitted with the main body of the scarf.
There are written instructions for the entire scarf. In addition, I have provided a chart for the lace border.
Of course you may work this pattern in whatever yarn takes your fancy, but please bear in mind that cotton viscose does not have the elasticity and memory of wool, and so does not curl nearly as much as wool, especially superwash, will.
The inherent nature of stocking stitch means there will be some curling if you choose to use a springy yarn.
Please bear in mind that curling is also exacerbated if you knit tightly, or if you tug too firmly when working the i-cord edge.