add a CODE_OF_CONDUCT.md

[domsbytes]

Add the file to root.

Use these resources below to write it out:

Formatting/ content guide:

• https://github.com/facebook/react/blob/main/CODE_OF_CONDUCT.md

Content should reflect our HQ COC as well:

• https://www.womenwhocode.com/codeofconduct

[domsbytes]

@ansh-saini completed in #45