Feedback on Filling Layouts article

[howardbaik]

Really cool package. I will be using this package for a dashboard, so I was reading the vignette on filling layouts and had one piece of feedback. I just discovered that the blue containers in the In theory section contains a tooltip when you hover over them. As a first-time reader, it wasn't terribly obvious what these blue containers were until I hovered my mouse over them. It would be helpful if you mentioned somewhere to readers to hover over them.