updated CAO content

Did some web editing work on the RASC TC site, updating CAO content. Added words to the spring work party page. Changed to a picture with people. I "unpublished" (i.e. hid) a bunch of the old work party announcement pages so to unclutter and reduce confusion. Touched up the bookings form. I'd really like to put words at the bottom near the MAKE RESERVATION button but that appears to not be possible. So I added a bit more text at the top. Oh, and I renamed articles to be more informative (CAO year title) and consistent. Wonder how many inward links I broke...