[Feat] README.md: Embed latest ARNEIS YouTube video

[gmacario]

📑 Description

Update video URL as a consequence of #246

✅ Checks

• [x] My pull request adheres to the code style of this project
• [ ] My code requires changes to the documentation
• [x] I have updated the documentation as required
• [x] All the tests have passed

ℹ Additional Information

[gmacario]

Do not merge until #120 is resolved

[gmacario]

Now that the webinar is public let's review and merge this PR

[gmacario]

@alv67 and @gteti since this will change the top-level README.md could you please double check before I merge this PR?