Update bug_report.md

Added this because of too many amateurs not following the obvious common steps before opening an issue.

.github/ISSUE_TEMPLATE/bug_report.md

@@ -36,3 +36,7 @@ If applicable, add screenshots to help explain your problem.
 
 **Additional context**
 Add any other context about the problem here.
+
+**Confirmation**
+- [ ] I have followed the template
+- [ ] I have checked the issues page, and this is not a duplicate