Typo's found by spell checker + trouble when setting up awestruct

While learning awestruct by using the ceylon site, I fixed a bunch of typo's in the the documentation directory.
Didn't see the spell check entirely through - so there are probably a lot left though.
(They are easy to flush out in IntelliJ in a list with right click on a directory, menu item "analyze", menu item "inspect code", but the list does contain a bunch of false negatives.)