Release notes--please review :) (#1477)
Release notes--please review :) (#1477)

* suggested changes
* spell fixes

ohsu-comp-bio/cromwell,ohsu-comp-bio/cromwell,broadinstitute/cromwell,broadinstitute/cromwell,ohsu-comp-bio/cromwell,broadinstitute/cromwell,broadinstitute/cromwell,broadinstitute/cromwell