move kitchen-sink demo into a separate directory

demo/docs/groovy.groovy

@@ -1,26 +0,0 @@
-//http://groovy.codehaus.org/Concurrency+with+Groovy
-import java.util.concurrent.atomic.AtomicInteger
-
-def counter = new AtomicInteger()
-
-synchronized out(message) {
-    println(message)
-}
-
-def th = Thread.start {
-    for( i in 1..8 ) {
-        sleep 30
-        out "thread loop $i"
-        counter.incrementAndGet()
-    }
-}
-
-for( j in 1..4 ) {
-    sleep 50
-    out "main loop $j"
-    counter.incrementAndGet()
-}
-
-th.join()
-
-assert counter.get() == 12