jobs: use "cmd: |", not "# keep first line ..."

Adjust README.adoc to mention "cmd: |" instead of the workaround and
replace this:
  cmd: >
   # keep first line with less indent to preserve newlines
    docker run ...

With that:
  cmd: |
    docker run ...

Change-Id: I65a06acb76e5d693aa187f9ac38970b73e7fead6
3 files changed