chore(docs): standardize markdown documentation

[meow2149]

This PR standardizes Markdown documentation across the repository to improve readability and consistency. No application logic or runtime behavior is changed.

• Unified heading hierarchy, lists, and language-tagged code blocks
• Normalized callouts (NOTE/TIP/WARNING) for important deployment notes
• Improved structure of installation/deployment guides for clearer step-by-step instructions
• Fixed minor doc issues (broken/incorrect relative links, inconsistent examples, trailing newline formatting)

Preview:
If you'd like to review the rendered output before merging, please check my fork: https://github.com/meow2149/HuLa-Server

Scope: documentation and README updates only (multiple .md files).

[meow2149]

Note

This PR touches many documentation files. I would appreciate a careful review to ensure the updated guides remain accurate and do not introduce anything that could accidentally mislead users during setup or deployment.

[nongyehong]

wow, thank you for your pr, I just saw it today, I've been busy with other projects recently, we'll review this pr as soon as possible, thank you 🙏

[nongyehong]

最近有点忙，又忘记审核了，刚才记起来，审阅没有问题，但是需要你解决一下冲突后我才可以合并。麻烦您了🙏