chore: added v0.19.x release notes (#172)
chore: added v0.19.x release notes (#172)

* chore: added v0.19.x release notes

* added more context to breakage

* correct-er wording this time

googleapis/google-cloud-cpp-common,googleapis/google-cloud-cpp-common,googleapis/google-cloud-cpp-common,googleapis/google-cloud-cpp-common