docs: fix grammar, typos, broken links, and documentation inconsistencies

[Gorghs]

Description

While reviewing the project's documentation, I identified several issues across multiple Markdown files. These include grammatical errors, spelling mistakes, incorrect or broken hyperlinks, mismatched HTML tags, and minor consistency issues.

Files affected

• CONTRIBUTING.md
• README.md
• ROADMAP.MD
• CHANGELOG.md

Proposed changes

• Fix grammar and spelling mistakes.
• Correct incorrect or outdated hyperlinks.
• Fix mismatched HTML tags in the README.
• Improve wording and documentation consistency.
• Resolve documentation inconsistencies where applicable.
• Rename ROADMAP.MD to ROADMAP.md for consistency across the repository (if maintainers approve).

Notes

These are documentation-only changes and will not affect the project's functionality.

If this contribution is acceptable, I'd be happy to work