Add Dockerfile and official docker image

[andyceo]

Hello!

Great utility, thank you a lot!

Would you like to add Dockerfile for that project and officially maintained docker image on Docker Hub to help users use this utility and reference building?

I made some and it work great! Take a look please: https://github.com/andyceo/dockerfiles/tree/master/lrzip and ready-to-use docker image: https://hub.docker.com/r/andyceo/lrzip/

I can fork this repository and provide Dockerfile for it. Please let me know if you are interested!