feat: Add GitHub community files and update contact information

This commit introduces standard GitHub community files including:
- Issue templates for bug reports and feature requests.
- Pull Request template.
- Security policy with contact email.
- Funding configuration with GitHub Sponsors and custom links.

Updates include:
- .github/ISSUE_TEMPLATE/ with bug_report.md and feature_request.md.
- .github/PULL_REQUEST_TEMPLATE.md.
- .github/SECURITY.md with tukuai.ai@gmail.com as contact email.
- .github/FUNDING.yml with github: tukuaiai and custom crypto/social links.
- README.md with a new 联系方式 section and fixed Mermaid diagram syntax.
- .gitignore updated to track .github/ directory.

This ensures better community engagement and project maintainability.

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,20 @@
+---
+name: 功能请求
+about: 提出一个新功能或改进现有功能
+title: "[Feature]: "
+labels: enhancement
+assignees: ''
+
+---
+
+**您希望解决什么问题？**
+清晰简洁地描述您希望通过此功能解决的问题。
+
+**您希望实现什么解决方案？**
+清晰简洁地描述您希望实现的解决方案。
+
+**考虑过的替代方案**
+清晰简洁地描述您已经考虑过的任何替代解决方案或功能。
+
+**附加信息**
+您在此处可以添加任何其他上下文信息或截图。