Contribute GitLab instructions to Karma documentation
Problem to solve
Karma documentation (http://karma-runner.github.io/) contains several introductions on how to set up karma in different CI providers, we should contribute how to get karma up and running on GitLab CI.
Further details
Proposal
Documentation submitted to Karma
What does success look like, and how can we measure that?
(If no way to measure success, link to an issue that will implement a way to measure this)