add template-override subdirectory to contrib and doc

    - This change introduces new template-override directories
      to store container template override files.
    - template override files stored in the contirb/template-override
      directory will not be gated and serve as an
      example of how to extend in-tree container images
      for specific use cases, e.g. source build of infra
      containers.
    - templates stored in contrib/template-override should
      have corresponding documentation in doc/template-override

Change-Id: I4c76b9338f92b779cc47b3f1147a816f0b683c6c

0 files changed, 0 insertions, 0 deletions