docs: fix contributing markdown (#598)
docs: fix contributing markdown (#598)


tschroed/envoy,dnoe/envoy,istio/envoy,dnoe/envoy,tdmackey/envoy,lyft/envoy,envoyproxy/envoy,eklitzke/envoy,craffert0/envoy,sebrandon1/envoy,jrajahalme/envoy,timperrett/envoy,envoyproxy/envoy-wasm,eklitzke/envoy,envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy-wasm,fengli79/envoy,istio/envoy,eklitzke/envoy,lizan/envoy,rlazarus/envoy,istio/envoy,lyft/envoy,lizan/envoy,envoyproxy/envoy,lizan/envoy,tschroed/envoy,lizan/envoy,timperrett/envoy,envoyproxy/envoy,istio/envoy,rlazarus/envoy,envoyproxy/envoy-wasm,dnoe/envoy,rlazarus/envoy,sebrandon1/envoy,jrajahalme/envoy,htuch/envoy,tdmackey/envoy,envoyproxy/envoy,amalgam8/envoy,lyft/envoy,tdmackey/envoy,amalgam8/envoy,jrajahalme/envoy,rlazarus/envoy,eklitzke/envoy,lyft/envoy,envoyproxy/envoy,istio/envoy,sebrandon1/envoy,istio/envoy,timperrett/envoy,lyft/envoy,amalgam8/envoy,htuch/envoy,craffert0/envoy,lizan/envoy,dnoe/envoy,craffert0/envoy,tdmackey/envoy,envoyproxy/envoy,istio/envoy,lizan/envoy,sebrandon1/envoy,envoyproxy/envoy-wasm,envoyproxy/envoy,envoyproxy/envoy,eklitzke/envoy,fengli79/envoy,amalgam8/envoy,dnoe/envoy,fengli79/envoy,craffert0/envoy,lyft/envoy,envoyproxy/envoy,eklitzke/envoy,jrajahalme/envoy,envoyproxy/envoy-wasm,timperrett/envoy,sebrandon1/envoy,envoyproxy/envoy-wasm,envoyproxy/envoy-wasm,jrajahalme/envoy,jrajahalme/envoy,htuch/envoy,tschroed/envoy,envoyproxy/envoy,fengli79/envoy