Enhance Code Consistency Across Repository with `.editorconfig`

[QuantumGhost]

Summary

This PR introduces a repository-wide .editorconfig file to ensure consistent formatting for all code.

The following changes are included:

• [x] Moved the existing .editorconfig file from the web directory to the repository root to centralize format definitions.
• [x] Added style configurations for additional languages, including Python, YAML, TOML, and Markdown.
• [ ] Pending: Set up corresponding CI checks to enforce these rules.

Closes #19021.

Screenshots

N/A

Checklist

[!IMPORTANT]
Please review the checklist below before submitting your pull request.

• [ ] This change requires a documentation update, included: Dify Document
• [x] I understand that this PR may be closed in case there was no previous discussion or issues. (This doesn't apply to typos!)
• [x] I've added a test for each change that was introduced, and I tried as much as possible to make a single atomic change.
• [x] I've updated the documentation accordingly.
• [x] I ran dev/reformat(backend) and cd web && npx lint-staged(frontend) to appease the lint gods