hg: openjfx/jfx-dev/rt: 8231326: Update README and CONTRIBUTING docs for Skara

[kevin.rushforth at oracle.com]

Changeset: d9abc7fbc1fc
Author:    kcr
Date:      2019-09-26 12:58 -0700
URL:       https://hg.openjdk.java.net/openjfx/jfx-dev/rt/rev/d9abc7fbc1fc

8231326: Update README and CONTRIBUTING docs for Skara
Reviewed-by: prr, jvos

! CONTRIBUTING.md
! README.md