RFR 8172183: Provide a javadoc description for jdk.dynalink module

[Jim Laskey (Oracle)]

+1

> On Jan 3, 2017, at 1:17 AM, Sundararajan Athijegannathan <sundararajan.athijegannathan at oracle.com> wrote:
> 
> Please review http://cr.openjdk.java.net/~sundar/8172183/webrev.00/ for https://bugs.openjdk.java.net/browse/JDK-8172183
> 
> Piggybacking couple of README cleanups in nashorn repo.
> 
> Thanks,
> -Sundar