docs: update quick start with build step

[eyevana]

Updated quick start instructions in README

What has changed and why

• I had to build all the components before running a local dev server in order for the demo site to work properly.

Ready-for-merge Checklist

• Expected files: all files in this pull request are related to one request or issue (no stragglers or scope-creep).
• Tests have been updated to cover these changes.
• Browser testing passed.
• Changelog updated.
• Documentation (README.md, WHY.md, etc.) updated or added.
• Link to the demo recording:
• Approved by designer.

Merging

Please squash when merging and ensure your commit message uses conventional commit formatting.

Be sure to share your updates with the patternfly-elements-contribute@redhat.com mailing list!

[changeset-bot]

⚠️ No Changeset found

Latest commit: 32cab4c

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR

[github-actions]

✅ Deploy Preview for patternfly-elements ready!

Name	Link
🔨 Latest commit	8e2660b
😎 Deploy Preview	https://deploy-preview-2307--patternfly-elements.netlify.app/

---

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

[bennypowers]

Thanks @eyevana!