Add code-of-conduct.md (#3122)
Add code-of-conduct.md (#3122)

Refer to kubernetes/community as authoritative source for code of conduct
GaneshSPatil/charts,rimusz/helm-charts,ledor473/charts,grugnog/charts,jainishshah17/charts,rimusz/helm-charts,jainishshah17/charts,lachie83/charts,samisms/charts,ledor473/charts,viglesiasce/charts,caiwenhao/charts,sd2k/charts,oleh-ozimok/charts,sd2k/charts,rimusz/helm-charts,viglesiasce/charts,GaneshSPatil/charts,rimusz/helm-charts,lachie83/charts,grugnog/charts,oleh-ozimok/charts,GaneshSPatil/charts,smelchior/charts,sd2k/charts,sd2k/charts,samisms/charts,viglesiasce/charts,helm/charts,smelchior/charts,lachie83/charts,helm/charts,lachie83/charts,GaneshSPatil/charts,smelchior/charts,helm/charts,grugnog/charts,oleh-ozimok/charts,helm/charts,ledor473/charts,samisms/charts,caiwenhao/charts,caiwenhao/charts,jainishshah17/charts