Well, running the surveys doesn't require any programming. It doesn't need knowledge in HTML or CSS.
But of course, like always, when you want to adapt the standard to your needs, then you need to have some basic knowledge in what you are doing, which would be HTML and CSS.
Of course, documentation could always be better, but keeping all the documentation is a lot of work. I have done little things here and there, but still not enough. But doing this gives you an idea what it means to keep the whole documentation on the level it is right now. So from my side:
Here a "Thank you" to all team members and users (yes, users can contribute, it's a wiki) that help to keep the Limesurvey documentation on this high level! Compared to many other projects, the documentation is really great.
. Are there any ideas for modifications...... 
, Mazi I will do my best and tell everybody about the great advantages of Limesurvey.