chore(readme): add link to code of conduct
chore(readme): add link to code of conduct

add link to code of conduct

rolandjitsu/ionic-app-scripts,michaelgeorgeattard/ionic-app-scripts,rolandjitsu/ionic-app-scripts,michaelgeorgeattard/ionic-app-scripts,michaelgeorgeattard/ionic-app-scripts,rolandjitsu/ionic-app-scripts,driftyco/ionic-app-scripts,driftyco/ionic-app-scripts,driftyco/ionic-app-scripts