Update issue templates

Author: AllenFang

.github/ISSUE_TEMPLATE/bug_report.md

@@ -8,7 +8,7 @@ assignees: AllenFang
 ---
 
 **Describe the bug**
-A clear and concise description of what the bug is.
+A clear and concise description of what the bug is. In addition, please search issues before you open a report to make sure there's no any duplicated report
 
 **To Reproduce**
 Steps to reproduce the behavior:

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,23 @@
+---
+name: Feature request
+about: Suggest an idea for this project
+title: ''
+labels: ''
+assignees: AllenFang
+
+---
+
+**Is this feature requested before?**
+Please search issues to make sure to create feature which is never report yet.
+
+**Is your feature request related to a problem? Please describe.**
+A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]
+
+**Describe the solution you'd like**
+A clear and concise description of what you want to happen.
+
+**Describe alternatives you've considered**
+A clear and concise description of any alternative solutions or features you've considered.
+
+**Additional context**
+Add any other context or screenshots about the feature request here.