[doc] Update README.md: experiemental => experimental

[Naereen]

Just a one word typo: experiemental => experimental, in the README.md

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[netlify]

✅ Deploy Preview for docsite-preview canceled.

Name	Link
🔨 Latest commit	198da88
🔍 Latest deploy log	https://app.netlify.com/sites/docsite-preview/deploys/6677a7010e72b9000833039e