Docs: Svelte docs and examples update

[jonniebigodes]

Follows up and Closes #23658

What I did

With this pull request the documentation was updated to:

• Feature TS and TS-4-9 examples
• Cleanup existing JavaScript variants
• Add conditionally rendering to some of the documentation as it's not available per current state of the framework (sections are identified as such with a comment)
• Fix snippets that were causing the documentation to break in a couple of places

@JReinhold when you have a moment can you take a look at this and let me know of any feedback you may have? Thanks in advance.

Checklist for Contributors

Testing

1. Follow the steps in the contributing instructions for this branch, docs_svelte_ts_example.
2. Open the relevant documentation and verify the feature changes.

The changes in this PR are covered in the following automated tests:

• stories
• unit tests
• integration tests
• end-to-end tests

Manual testing

This section is mandatory for all contributions. If you believe no manual test is necessary, please state so explicitly. Thanks!

Documentation

• Add or update documentation reflecting your changes
• If you are deprecating/removing a feature, make sure to update
  MIGRATION.MD

Checklist for Maintainers

• When this PR is ready for testing, make sure to add ci:normal, ci:merged or ci:daily GH label to it to run a specific set of sandboxes. The particular set of sandboxes can be found in code/lib/cli/src/sandbox-templates.ts

• Make sure this PR contains one of the labels below:

  Available labels

  • bug: Internal changes that fixes incorrect behavior.
  • maintenance: User-facing maintenance tasks.
  • dependencies: Upgrading (sometimes downgrading) dependencies.
  • build: Internal-facing build tooling & test updates. Will not show up in release changelog.
  • cleanup: Minor cleanup style change. Will not show up in release changelog.
  • documentation: Documentation only changes. Will not show up in release changelog.
  • feature request: Introducing a new feature.
  • BREAKING CHANGE: Changes that break compatibility in some way with current major version.
  • other: Changes that don't fit in the above categories.

🦋 Canary release

This PR does not have a canary release associated. You can request a canary release of this pull request by mentioning the @storybookjs/core team here.

core team members can create a canary release here or locally with gh workflow run --repo storybookjs/storybook canary-release-pr.yml --field pr=<PR_NUMBER>

[JReinhold]

LGTM! ❤️