add docker support

[Alistair1231]

Last one I made the pull request from the master branch on accident, so here we go again 😄

I thought I would try to make setup easier for people, so I made the project run in docker. This is my first time working with Perl, so please let me know if I made some glaring mistakes. It took me a while, but I finally got it working.

Please let me know if I should change something. :)