[FEATURE] Improve yuck documentation

[ghistes]

I would like to understand what configuration directives actually do.

In "Creating your first window" the directive

  :reserve (struts :distance "40px" :side "top")

is used and while the ":reserve"-keyword is at least rudimentary explained, there is no information at all about what "struts" does. It may seem obvious to people with experience in X11-programming but if you lack that background-knowledge it remains a mystery that you may have theories about (I assume you have to supply distance and side, but who knows...) but all you really can do is guess and experiment...

[elkowar]

while the word struts may be a magical technical word that people don't get (and that should probably be explained, I agree) - the words distance and side should make it pretty clear that you, well, have to specify the distance to a given side, no?