Update issue templates (#454)

Author: Keen Yee Liau

.github/ISSUE_TEMPLATE/bug_report.md

@@ -2,8 +2,9 @@
 name: Bug report
 about: Create a report to help us improve
 title: ''
-labels: ''
+labels: bug
 assignees: ''
+
 ---
 
 **Describe the bug**