Add internationalization

I'm not quite sure how to do this, so I'm open to suggestions if someone else wants to tackle it. The idea would be to take the instructions and logging and allow users to change their language so they can read the instructions in their native language.

It would also be nice to look up their language and change it for them.

No files or tests are named, so first inspect the project entry points that produce instructions and logging. Define the supported language-selection behavior, including whether a user's language can be detected automatically; done means both instructions and log output can be read in the selected language.

Written by the indexing model from the issue text.