docs(previews): Fix examples, update example readmes

[ahuseyn]

Description

Updates README documentation and wp-env configuration for both HWP Previews examples (REST and WPGraphQL) to improve clarity and usability.

Changes:

• Documentation: Added frontmatter with title and description to both example readmes
• README improvements: Reorganized installation steps, clarified instructions, and fixed typos
• Plugin source: Updated .wp-env.json to use published plugin releases instead of local paths for better portability
• Better structure: Improved readability with clearer section headings and step-by-step instructions

Related Issue

• chore(previews): Validate examples and improve scripts #509

Dependant PRs

Type of Change

• ✅ Bug fix (non-breaking change which fixes an issue)
• ✨ New feature (non-breaking change which adds functionality)
• 💥 Breaking change (fix or feature that would cause existing functionality to change)
• 🧹 Code refactoring (no functional changes)
• 📄 Example update (no functional changes)
• 📝 Documentation update
• 🔍 Performance improvement
• 🧪 Test update

How Has This Been Tested?

Screenshots

Checklist

• I have read the CONTRIBUTING document
• My code follows the project's coding standards
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation (if applicable)
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works (if applicable)
• Any dependent changes have been highlighted, merged or published

[changeset-bot]

⚠️ No Changeset found

Latest commit: 3838dcc

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

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[github-actions]

📦 Plugin Artifacts Ready!

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Available plugins:

• ✅ hwp-previews.zip

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