Improve Content resource pages

I'm looking for help to complete the [Content page](../tree/master/arcgis/content), and the subpages under it. I made a "[resource page template](https://github.com/esri-es/awesome-arcgis/blob/master/RESOURCE_PAGE_TEMPLATE.md)" to give some guidance on how a *product resource page* could look like. But maybe it doesn't fit 100% for this kind of page.