[Integrated] RFR: doc: update README

[Erik Helin]

Changeset: 3cf06964
Author:    Erik Helin <ehelin at openjdk.org>
Date:      2020-03-02 14:12:28 +0000
URL:       https://git.openjdk.java.net/skara/commit/3cf06964

doc: update README

Reviewed-by: rwestberg

! Makefile
! README.md