Add a doc on general troubleshooting tips. (#1275)
Add a doc on general troubleshooting tips. (#1275)

* Add a doc on general troubleshooting tips.

* fixup! Add a doc on general troubleshooting tips.

* fixup! fixup! Add a doc on general troubleshooting tips.
google/exposure-notifications-verification-server,google/exposure-notifications-verification-server,google/exposure-notifications-verification-server,google/exposure-notifications-verification-server