Add legally required/advised-to-have files to the root of the site

* Requested for the IP review for Graphiti 0.18.0 and Eclipse 2021-06

Bug: https://gitlab.eclipse.org/eclipsefdn/emo-team/emo/-/issues/45
Change-Id: I7a9ab929d4eca792d8299c586fca99e7ce86ce05
7 files changed
tree: 0b3aa0978b5427a3ec1f4079eea8738a9636463a
  1. CONTRIBUTING.md
  2. examples/
  3. features/
  4. parent/
  5. plugins/
  6. releng/
  7. tests/