Add a local CONTRIBUTING.md file that points to the main one on istio/community. (#1871)
Add a local CONTRIBUTING.md file that points to the main one on istio/community. (#1871)

Having this file present helps our community-friendly rating that GitHub maintains.
istio/istio,smawson/istio,istio/istio,frankbu/istio,geeknoid/istio,geeknoid/istio,smawson/istio,istio/istio,frankbu/istio,geeknoid/istio,geeknoid/istio,frankbu/istio,istio/istio,smawson/istio,smawson/istio,smawson/istio,frankbu/istio,geeknoid/istio,frankbu/istio,smawson/istio,frankbu/istio,istio/istio,geeknoid/istio