Added lower than IE9 incompatibility notice
Added lower than IE9 incompatibility notice

telusdigital/pagerduty-dashboard,telusdigital/application-pagerduty-dashboard,killerwails/pagerduty-dashboard,gondek/pagerduty-dashboard,telusdigital/application-pagerduty-dashboard,killerwails/pagerduty-dashboard,telusdigital/pagerduty-dashboard,gondek/pagerduty-dashboard