flaky-test-retryer: add readme (#1221)
flaky-test-retryer: add readme (#1221)

* flaky-test-retryer: add readme

* Apply suggestions from code review

Co-Authored-By: srinivashegde86 <35474de38fdc96533349a4090852a4ac16e8ddf5@google.com>

* change configuration wording

* add troubleshooting contact

* Apply suggestions from code review

Co-Authored-By: srinivashegde86 <35474de38fdc96533349a4090852a4ac16e8ddf5@google.com>

knative/test-infra,knative/test-infra,knative/test-infra