Minor tweaks to CONTRIBUTING.md
Minor tweaks to CONTRIBUTING.md

mpolednik/kubevirt,stu-gott/kubevirt,mpolednik/kubevirt,kubevirt/kubevirt,fabiand/kubevirt,davidvossel/kubevirt,kubevirt/kubevirt,davidvossel/kubevirt,admiyo/kubevirt,rmohr/kubevirt,davidvossel/kubevirt,kubevirt/kubevirt,stu-gott/kubevirt,stu-gott/kubevirt,davidvossel/kubevirt,admiyo/kubevirt,rmohr/kubevirt,fabiand/kubevirt,stu-gott/kubevirt,kubevirt/kubevirt