Improved the community docs.

- Added the PR template & code of conduct
- Improved the issue templates.

.github/ISSUE_TEMPLATE/bug_report.md

@@ -4,36 +4,44 @@ about: Create a report to help us improve
 labels: bug
 ---
 
-<!-- Please make sure you have read the README or Wiki, and your question does not appear in other existing issues (including closed ones). Thanks for your cooperation! Now let's start it. -->
+# Checklist
+<!-- Please complete the following list of tasks, and then check it by change the "[ ]" to "[x]" -->
+- [ ] I have read the [tutorials](https://chirpy.cotes.info/categories/tutorial/) and know the correct effect of the functional design.
+- [ ] There are no similar reports on existing issues (including closed ones).
+- [ ] I found the bug on the latest code of `master` branch.
 
-**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. -->
 
-**Desktop (please complete the following information):**
+## Desktop:
+<!-- Please complete the following information -->
  - OS: [e.g. iOS]
  - Browser: [e.g. chrome, safari]
  - Version: [e.g. 22]
 
-**Smartphone (please complete the following information):**
+## Smartphone:
+<!-- please complete the following information -->
  - Device: [e.g. iPhone6]
  - OS: [e.g. iOS8.1]
  - Browser: [e.g. stock browser, safari]
  - Version: [e.g. 22]
 
-**Additional context**
+## Additional context
 <!-- Add any other context about the problem here. -->