Document how to set up custom Sentry alerts per-team
Document how to set up custom Sentry alerts per-team

Trello: https://trello.com/c/izP3qFWg/2516-document-how-teams-can-set-up-sentry-slack-alerts

alphagov/govuk-developer-docs,alphagov/govuk-developer-docs,alphagov/govuk-developer-docs,alphagov/govuk-developer-docs