add information about running with gunicorn

README.md

@@ -41,5 +41,10 @@ INCIDENT_URL_SCHEME = STATUS_PAGE_URL + "event/%s/"
 export FIH_SETTINGS=~/incident_handler/settings.cfg
 export FLASK_APP=fih.py
 cd ~/incident_handler
+
+# for development
 flask run -p 3333
+
+# for production
+gunicorn -w 4 -b 127.0.0.1:3333 fih:app
 ```