add triage labels to bug report (#612)

Author: jennyf19

.github/ISSUE_TEMPLATE/bug_report.md

@@ -1,8 +1,8 @@
 ---
 name: Bug report
 about: Create a report to help us improve
-title: ''
-labels: ''
+title: '[Bug] '
+labels: ["untriaged", "needs attention"]
 assignees: ''
 
 ---