Rename stable plugins from -proposal- to -transform-

[nicolo-ribaudo]

Docs for https://github.com/babel/babel/pull/15614

[netlify[bot]]

✅ Deploy Preview for babel-next ready!

Name	Link
🔨 Latest commit	0f61546fe4ad8acaad64677dee52f0d3a79c9e99
🔍 Latest deploy log	https://app.netlify.com/sites/babel-next/deploys/647088c28a04b500091acd05
😎 Deploy Preview	https://deploy-preview-2787--babel-next.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.

[netlify[bot]]

✅ Deploy Preview for babel ready!

Name	Link
🔨 Latest commit	0f61546fe4ad8acaad64677dee52f0d3a79c9e99
🔍 Latest deploy log	https://app.netlify.com/sites/babel/deploys/647088c290b770000868844a
😎 Deploy Preview	https://deploy-preview-2787--babel.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.