RFR: 1102: Document minimum required JDK version 16 for Skara [v2]

[Iris Clark]

On Wed, 7 Jul 2021 20:13:23 GMT, Erik Joelsson <erikj at openjdk.org> wrote:

>> Change documentation to reflect that Skara now requires JDK 16 to build.
>
> Erik Joelsson has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Update example

Marked as reviewed by iris (no project role).

-------------

PR: https://git.openjdk.java.net/skara/pull/1195