chore: Enhance style

.github/ISSUE_TEMPLATE/2_bug_report.md

@@ -7,25 +7,31 @@ assignees: peaceiris
 
 ---
 
-**Describe the bug**
+### Describe the bug
+
 A clear and concise description of what the bug is.
 
-**To Reproduce**
+### To Reproduce
+
 Steps to reproduce the behavior:
 1. Go to '...'
 2. Click on '....'
 3. Scroll down to '....'
 4. See error
 
-**Expected behavior**
+### Expected behavior
+
 A clear and concise description of what you expected to happen.
 
-**Screenshots**
+### Screenshots
+
 If applicable, add screenshots to help explain your problem.
 
-**Your YAML file**
+### Your YAML file
+
 - A link to your repository
 - A link to your YAML file
 
-**Additional context**
+### Additional context
+
 Add any other context about the problem here.