For example, if you write LaTeX files for you PDFs, give both PDFs and the LaTeX.
This allows other people to:
  • modify and reuse your material
  • make improvement suggestions that you can accept by clicking a button
    The perfect way to do this is to use GitHub pull requests
Whenever you make a change to your material, people should still be able to access the previous version.
Maybe there was something in the previous version that they needed, and you just removed.
Git + GitHub is the perfect way to do versioning.