[zanata/zanata-root] 8b0a54: update instruction for how to use git submodule

[GitHub]

  Branch: refs/heads/integration/master
  Home:   https://github.com/zanata/zanata-root
  Commit: 8b0a54bf3e0adf905c511607012946b47fdc594b
      https://github.com/zanata/zanata-root/commit/8b0a54bf3e0adf905c511607012946b47fdc594b
  Author: Patrick Huang <pahuang at redhat.com>
  Date:   2015-07-17 (Fri, 17 Jul 2015)

  Changed paths:
    M README.md

  Log Message:
  -----------
  update instruction for how to use git submodule