[MEMO] Made minor edit on contributing.md
[MEMO] Made minor edit on contributing.md

bbtran/Regexcellence,hellodanali/Regexcellence,Regexcellence/Regexcellence,hellodanali/Regexcellence,lwonsower/Regexcellence,lwonsower/Regexcellence,bbtran/Regexcellence,Regexcellence/Regexcellence