Update port placement module to use Markups module

Comparison between versions:

https://github.com/giogadi/PortPlacement/compare/giogadi:0dd35b09c5c34126d917cc3c0c86cb265a908919%E2%80%A6giogadi:48b20ae48fcf02ed85b7ba9abf910e0edc92a9b3