Create dsql-primer project

[romaninsh]

DSQL has a lot of flexibility, but it's quite difficult to demonstrate with documentation alone.

The idea is to start a new project, that will consist of a very basic PHP files. When you execute those files, they will perform a query and fetch result from a "employee" data-set.

This will make it much easier for new users to learn DSQL.

[romaninsh]

https://github.com/atk4/dsql-primer - project is created and the first working version is posted. Other contributors are welcome to extend it.