Go-CLI: A txtar template for creating a Go CLI application

See https://blog.carlmjohnson.net/post/2020/go-cli-how-to-and-advice/ for background on this project.

To use this template to create a Go CLI:

1. Install Go and springerle
2. Run springerle https://github.com/carlmjohnson/go-cli/raw/master/go-cli.txtar and answer prompts for information.
3. Verify the contents of the files written to disk, then run ./finalize.sh to download Go dependencies and initialize the git repo.