This is mainly about customizations made to service configuration in V2 and how to make those in V3
Documents to update are:

• https://docs.edgexfoundry.org/3.0/microservices/core/data/Ch-CoreData/#v3-configuration-migration-guide
• https://docs.edgexfoundry.org/3.0/microservices/core/metadata/Ch-Metadata/#v3-configuration-migration-guide
• https://docs.edgexfoundry.org/3.0/microservices/core/command/Ch-Command/#v3-configuration-migration-guide
• https://docs.edgexfoundry.org/3.0/microservices/support/notifications/Ch-AlertsNotifications/#v3-configuration-migration-guide
• https://docs.edgexfoundry.org/3.0/microservices/support/scheduler/Ch-Scheduler/#v3-configuration-migration-guide