chore: add a Code of Conduct (#39)
chore: add a Code of Conduct (#39)

Co-authored-by: google-cloud-policy-bot[bot] <92a6cf9f50641a93109ccdcf7086298233589fca@users.noreply.github.com>
Co-authored-by: Justin Beckwith <0b357449eb5b1ce3bad523b6be0681e856776d8e@gmail.com>
googleapis/protoc-docs-plugin