Add missing standard community files like code of conduct

[mhucka]

We currently lack certain standard community-oriented files recommended by Google OSPO guidelines, such as a code of conduct, SUPPORT.md, and possibly others. This is a fairly trivial chore that just needs us to do a quick check and add the necessary files.

[Aniketsy]

@mhucka , In addition to CODE_OF_CONDUCT.md and SUPPORT.md, do you think we should also add a GOVERNANCE.md file to clarify the project’s decision .
Let me know your thoughts!