feature_request(enhancement): exit codes

[Kristinita]

1. Summary

It would be nice, if exit codes will be implemented to textr.

If need typography replacement in a file:

    exit code ≠ 0

else file doesn't need replacements:

    exit code == 0

2. Argumentation

For Continuous Integration.

I have many files, which need to be checked (example). I use Continuous Integration (Travis CI and AppVeyor) to check the files with several programs. I do this for the same purpose that CI uses when developing software: it helps automatically and quickly find errors in texts, without needing local programs run. If exit codes exists → my build failed → I get a notification that somewhere in my files there is an error. It's comfortable.

Thanks.

[denysdovhan]

Shouldn't be hard to implement. Would you like to help?