Update README with new CSS handles

[victorhmp]

What is the purpose of this pull request?

Update README file with new CSS handles created by PR #90 .

What problem is this solving?

Outdated docs. Should close vtex-apps/io-documentation#382

Types of changes

• 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)
• Requires change to documentation, which has been updated accordingly.

[vtex-io-ci-cd]

Hi! I'm VTEX IO CI/CD Bot and I'll be helping you to publish your app! 🤖

Please select which version do you want to release:

• Patch

• Minor

• Major

And then you just need to merge your PR when you are ready! There is no need to create a release commit/tag.

• No thanks, I would rather do it manually 😞

[vtex-io-docs-bot]

Beep boop 🤖

Thank you so much for keeping our documentation up-to-date ❤️

[vtex-io-ci-cd]

Your PR has been merged! App is being published. 🚀
Version 2.17.1 → 2.17.2