Add an episode about using git LFS

• It should be a basic introduction
  • Explain its use case, how it basically works and what is different in comparison to plain git
  • Explain the setup
  • Explain the modify, add, commit workflow with files managed by git LFS (Git + GitLab
  • Explain how locks can be used (Git + GitLab)
• The episode should fit into a 60-90min slot
• It might include a small team exercise if possible => seems be already too much for 90min