Docs: Add code snippets for yarn pnp in migration-guide

[jackw]

Closes #21895

What I did

Updates the docs to include commands for yarn pnp for migrating.

How to test

Checklist

• Make sure your changes are tested (stories and/or unit, integration, or end-to-end tests)
• Make sure to add/update documentation regarding your changes
• If you are deprecating/removing a feature, make sure to update
  MIGRATION.MD

Maintainers

• If this PR should be tested against many or all sandboxes,
  make sure to add the ci:merged or ci:daily GH label to it.
• Make sure this PR contains one of the labels below.

["cleanup", "BREAKING CHANGE", "feature request", "bug", "documentation", "maintenance", "dependencies", "other"]

[jonniebigodes]

@jackw thanks for taking the time to create this pull request and help us improve our documentation. We appreciate it. I left a small item that requires your attention and this should be good to go.

Let me know once you've addressed it and we'll take it from there.

Hope you have a great day.

Stay safe

[jackw]

Let me know once you've addressed it and we'll take it from there.

@jonniebigodes I've updated the PR as requested. Let me know if you need anything more from my side.

[jonniebigodes]

@jackw sorry for the delayed response 🙏 . I just have one final item for you to address so that we can merge this pull request.

Let me know once you have addressed the feedback and I'll gladly merge it.

Hope you have a great week

Stay safe

[jonniebigodes]

@jackw Thanks for making the changes so promptly. I just got the notification about the latest commit. I'm going to merge this pull request once the checklist clears. Once again, thank you so much for taking the time to put together this pull request and help us improve our documentation 🙏