More newbie-oriented tour

[wilzbach]

While having a look at #193, I realized that the tour isn't well suited for someone with no or little programming background as we don't explain any basics like variables or pointers.

As our main target are experienced programmers, that's ok - however imho we could try to target beginners too. I am not sure yet what is the best way to do this, but an idea would be to have a "freshup section" to which we point in the beginning - like e.g. "New to pointers? Read this".

[wilzbach]

This issue was moved to dlang-tour/english#27