Add a directory to provide examples

[daviderli614]

New directory structure such as:

example
- objectstorage
-- oss
--- README.md
--- values.yaml

-- s3
--- README.md
--- values.yaml

-- gcs
--- README.md
--- values.yaml

- logging
-- README.md
-- values.yaml

- auth
-- README.md
-- values.yaml

- ...

[zyy17]

I think we can create a examples/ in the root directory.