Use the common docs from `google/open-source-pdks` repository. * Use a symlink to include `third_party/open-source-pdks/docs` under the local docs. * Add top level `CODE_OF_CONDUCT.md` file which points to the actual code of conduct location. * Add top level `CONTRIBUTING.md` file which points to the actual contributing guidelines. Signed-off-by: Tim 'mithro' Ansell <tansell@google.com>