But why that long, and why that expensive !?

find ./ -name "*.as" -o -name "*.php" -o -name "*.js" -o -name "*.ctp" -o -name "*.thtml" -o -name "*.css" -o -name "*.html" -type f|xargs cat >> ./readme.txt

Unfortunately you need to actually get it done in order to use the above command :D