Update README, Add Issue and PR templates

[xing-yiren]

Descirption

Update README, Issue and Pull Request Templates for repository refactorization.

Changes

1. Updated README.md and README_ZH.md using the new template

• The original repository README has been archived as README_BAK.md. Please revise the new README templates using information from the backup. After completing the updates, delete the README_BAK.md file.

2. Added Issue and Pull Request templates

• Please test the new templates to ensure they work as expected. Remember to update the Contributing Guideline link in PULL_REQUEST_TEMPLATE

3. CI and other GitHub Actions

• Continuous Integration (CI) workflows and other GitHub Actions will be introduced in a follow-up PR after the template tests are completed.

[wang-hua-2019]

确认一下为什么数字改为null

[xing-yiren]

• 原因：是因为本地的 Jupyter 版本与代码仓中 Notebook 的创建版本不一致，打开文件时会自动将未激活的单元格execution_count重置为null（新版本默认对未执行单元格不显示计数）
• 解决方案： 考虑到不同人运行 Notebook 会产生不同的execution_count、输出结果，提交后容易导致 Git 冲突；且Notebook 的输出（如图片、大段文本）会让文件体积变大，建议提交notebook前，通过nbstripout剔除运行时产生的动态数据，仅保留代码、Markdown 文本结构，让文件更干净
• 具体操作：
  fork并clone代码仓后，执行：

  pip install nbstripout
  nbstripout --install

  上述操作后，后续每一次提交时，Git 都会自动调用nbstripout清理.ipynb文件的过程数据

[xing-yiren]

修改已提交至dev分支：#143