Documentation RunSQL - add example and emphasis that sqlparse is required

There is no ticket opened for this change, let me know if we need one.

I found that example for RunSQL is very good to have specially as this is all quite new to Django
I prefer not using note boxes if possible, but if you do use them, please indent 4 spaces instead of 2. Having the sentences next to where ``sql`` and ``sqlreverse`` are discussed would be preferable.