Implementing shared-styles into displayHTML

Working through trying to get displayHTML working, I used all inline styling to get things working initially. I just noticed some documentation about shared-styles on github. More specifically, it states that the SASS compiler needs to be restarted when you make changes to shared-styles. How can one recompile the scss?

According to
We need to update the sanitizer or the shared-styles folder but both of those folders are ignored by the node package manager.