Add Xquik API Workflows skill

[kriptoburak]

Summary

• Add an installable Xquik API Workflows skill with SKILL.md frontmatter.
• Add the skill to the Skills with MCP catalog section.
• Normalize 2 existing README punctuation characters touched by this edit.

Checks

• Duplicate gate: memory checked, default branch searched for Xquik names and package aliases, and all-state PRs/issues reviewed. Existing Hermes and TweetClaw routes are excluded by scope, with no non-excluded Xquik duplicate found.
• Source truth: public Xquik docs, GitHub source package, and npm x-developer metadata checked.
• Validation: frontmatter and catalog path check, Git whitespace check, added-line public-surface scan, and link checks for docs and source URLs.