Add Xquik API documentation and alphabetize the API section

[kriptoburak]

🚀 Pull Request

📄 Description

• Add Xquik API Documentation to the API section.
• Describe the current REST, OpenAPI, MCP, webhook, and workflow documentation.
• Alphabetize all 25 API entries, contributing to Most sections need to be alphabetized #28.

The independent ordering fix moves DevDocsAI and corrects the ReDoc ordering. It remains separate from the Xquik addition.

Validation

• Confirmed the complete API section sorts alphabetically.
• Confirmed all 4 affected links return HTTP 200.
• Confirmed one Xquik entry and one DevDocsAI entry.
• Confirmed the branch is based on current main.
• Confirmed both commits are signed and GitHub-verified.
• Ran git diff --check.

Xquik is an independent third-party service. Not affiliated with X Corp. "Twitter" and "X" are trademarks of X Corp.

[kriptoburak]

A final rules audit found one remaining API ordering inversion: ReDoc followed Redoc-Editor. I rebuilt the branch as 2 signed commits. The independent commit now leaves all 25 API entries alphabetized. All 4 affected links return HTTP 200, both entries remain unique, and git diff --check passes.