this code is the following tutorial.
https://go.dev/doc/tutorial/create-module

you can build and install this package to your local machine.

cd hello
go build
go install

you must add your module install dir to $PATH.

export PATH=$PATH:/path/to/your/install/directory

you can run it.

hello
# map[Darrin:Great to see you, Darrin! Gladys:Hail, Gladys! Well met! Samantha:Great to see you, Samantha!]