New documentation

[kablag]

New documentation

[michbur]

I read only a head of the issue and thought that you mean roxygenization. Done it, feel free to reset repo if it isn't suiting you.

[kablag]

Thanks for your work!!! I'll use it as template. But now I'am at the middle of rewritting all functions with R6 objects and documantation should be changed after that. I'll send you a message after all things will be done. Please, don't commit before that, because many things may changed.