feat: add shake effect animation submission

[Shreeya1207]

Description

This PR adds a new submission demonstrating a Shake Effect animation utility.

Added Effect

• shake-effect

Files Added

• submissions/examples/ease-shake-effect/demo.html
• submissions/examples/ease-shake-effect/style.css
• submissions/examples/ease-shake-effect/README.md

Demo

The demo showcases a hover-triggered shake animation that moves elements horizontally to create visual emphasis. The effect is smooth, lightweight, and can be easily applied to different UI components.

Why

Shake animations are commonly used to draw attention to important elements, indicate errors, highlight actions, or provide interactive feedback. This utility offers a reusable and easy-to-understand implementation that aligns with EaseMotion CSS's philosophy of expressive and human-readable animation utilities.

Checklist

• Added files only inside submissions/
• Included demo.html
• Included style.css
• Included README.md
• One feature per PR
• Demo works without external dependencies
• Followed contribution guidelines

[github-actions]

✅ Submission Validation Passed!

Great job! All required files are present.

📁 Folder: submissions/examples/ease-shake-effect

Files found:

• ✅ demo.html
• ✅ style.css
• ✅ README.md

🚀 Next Steps:

• The maintainer will review your PR
• Respond to any feedback if requested
• Once approved, your contribution will be merged!

Thank you for contributing to EaseMotion CSS! 🎉