hg: jmc/jmc: JMC-6421: Small correction to README to make it simpler to copy past for building JMC

[neugens.limasoftware at gmail.com]

Changeset: cb6637d0b521
Author:    neugens
Date:      2019-02-27 13:52 +0100
URL:       http://hg.openjdk.java.net/jmc/jmc/rev/cb6637d0b521

JMC-6421: Small correction to README to make it simpler to copy past for building JMC
Summary: Reword instructions so that they can be copy/pasted in terminal directly
Reviewed-by: hirt

! README.md