Document unleash client functionality on the repository and launch our Beta

We need to have full usage instructions on how to use our unleash client. This should be as community facing as possible, so we can send it over to Unleash and get the accolades we deserve.

• Add a status badge to show the state of our tests
• Make sure master is protected and we can only push in via MRs
• Document environment variables and configuration
• Installation instructions
• Document using our strategies
• Document Gitlab integration
• Publish our vendor package

When this is done, I'll send it over to the unleash maintainers for linking and feedback