docs: add MainWP Labs tagline to README

[dennisdornon]

Summary

• Add italicized "A MainWP Labs project, powered by MainWP" tagline below the header
• Links "MainWP Labs" to https://mainwp.com/mainwp-labs/

Test plan

• Verify tagline renders correctly on GitHub
• Confirm link works

Summary by CodeRabbit

• Documentation
  • Updated project description in README with a new tagline clarifying the MainWP Labs affiliation and project attribution.

[coderabbitai]

Caution

Review failed

The pull request is closed.

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 1e542a2c-73d7-4f08-8d95-51596b568541

📥 Commits

Reviewing files that changed from the base of the PR and between 0fe4dd2 and 8448737.

📒 Files selected for processing (1)

• README.md

Disabled knowledge base sources:

• Linear integration is disabled

You can enable these sources in your CodeRabbit configuration.

---

Walkthrough

The README.md is updated with a new italicized tagline line beneath the main heading, identifying the project as a MainWP Labs initiative powered by MainWP. No other content or structure changes are made.

Changes

Cohort / File(s)	Summary
Documentation README.md	Adds an italicized tagline describing the project as a MainWP Labs initiative under the main heading.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~2 minutes

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch docs/readme-tagline

---

_{Comment @coderabbitai help to get the list of available commands and usage tips.}