This is the main overview page for your dataset, where you can edit the description, readme, and tags associated with the dataset. All fields are optional, you can add as little or as much as you would like. The readme renders as regular markdown, but using markdown syntax is not required.
Below is an example of an overview page with content in all the sections mentioned above:
If your dataset contains saved queries they will populate in a table below the content section, as seen in the image.