[lang] Add SQL

[aminoxix]

Current Behavior

This project doesn't have SQL language, not even in the pull request I find something relates fs!

Desired Behavior

SQL language must be considered inside the lang folder.

Implementation

The way of implementation listed on README.md, section consisting contribution guidelines.

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Contributor Guides and Resources

• 🛠 Reference for building
• 📚 Instructions for contributing to documentation
• :exclamation: Code of Conduct
• 🙋🏾🙋🏼 Questions: Discord discussion server