Go Class: 27 Concurrent File Processing

This segment shows a sequential program to walk a directory tree and process files and then three concurrent versions, demonstrating how to orchestrate channels and manage the workload. I also introduce the WaitGroup concurrency primitive. Slides at: https://github.com/matt4biz/go-class-slides/blob/trunk/xmas-2020/README.md Code at: https://github.com/matt4biz/go-class-walk