Make examples in quickstart all work.

Hi, when working through the quickstart document I found it a little confusing that I couldn't type along the examples and make them work.

When creating the table in the 'Storing data' section the table created
was called 'person', rather than 'user' making the other examples not
work because 'user' was referred to rather than 'person'.

I added countries to the entered data so that later queries in the
quickstart return some data.

I changed examples of returned data in 'Inspecting databases and tables'
match what is actually returned.

In 'Reading data from tables' I make the examples return real data.