pipelines folder
This folder contains Azure DevOps pipelines that gets migrated to the Azure DevOps instance.
Note any file added to this folder or sub folders will get migrated to the Azure DevOps instance when the GitHub Action runs to create and bootstrap the Azure DevOps project
classic folder
The classic folder contains classic style Azure DevOps pipelines that are pure JSON files.
yml folder
The yml folder contains yml Azure DevOps pipelines.