Add Xquik API

[kriptoburak]

Summary

• Add Xquik to the API catalog as an authenticated Social Media API.
• Include the public docs URL, API base URL, example endpoint, tags, response format, auth, and pricing metadata.

Validation

• python3 -m json.tool catalog/apis.json
• Catalog schema and duplicate-id validation script
• git diff --check
• URL checks for https://xquik.com and https://docs.xquik.com/api-reference/overview

[kriptoburak]

If this is useful and you merge it after checks pass, feel free to share the PR on X/Twitter and mention my handle, burakbayir. I can repost or retweet it to my 24k followers of developers and power users, which may help more relevant users discover this repo.