Has a basic 5-column, 6-row layout, with padding/spacing columns/rows delineated with coloured boxviews (since gridview cells don't have borders, we can't see where one cell stops and another begins)
Note, to get the design-time intellisense for the DataContext binding, you'll need to add the following namespaces to the top of your XAML file (can go beneath the usual xamarin forms namespaces, order isn't really important):
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"