replace decorations png by svg + adjust their size

[ghost]

fixes #70

[netlify[bot]]

✅ Deploy Preview for startling-capybara-2231ea ready!

Name	Link
🔨 Latest commit	b6119a7764cd263953325e1732e6fc531c29358c
🔍 Latest deploy log	https://app.netlify.com/sites/startling-capybara-2231ea/deploys/631b675500211e000987ddf1
😎 Deploy Preview	https://deploy-preview-82--startling-capybara-2231ea.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site settings.