fix(v5): broken link and missing type annotations in tutorial

[ArmandPhilippot]

I know we're not supposed to send PRs right now, but since I noticed some errors while I did the tutorial again (see withastro/blog-tutorial-demo#33), I thought I'd make the necessary updates!

Description (required)

Updates the tutorial to:

• Add missing type annotations in the Unit 5 (final code snippet, code check-ins...)
• Fix a broken link in Unit 6

I haven't addressed ThemeIcon.astro because I don't know if it's necessary or not:

• when I follow the tutorial I don't see any error
• when I open blog-tutorial-demo I see Typescript errors...

Related issues & labels (optional)

• Suggested label: 5.0.0-beta, code snippet update, typo/link/grammar - quick fix!

Sorry for the wrong automatic labels... I forgot to use the 5.0.0 branch as base... 😅

[netlify]

✅ Deploy Preview for astro-docs-2 ready!

Name	Link
🔨 Latest commit
🔍 Latest deploy log	https://app.netlify.com/sites/astro-docs-2/deploys/674b487d2e8d246d9e33b5b2
😎 Deploy Preview	https://deploy-preview-10119--astro-docs-2.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

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

[astrobot-houston]

Lunaria Status Overview

🌑 This pull request will not trigger status changes.

Learn more

Lunaria automatically ignores changes on specific PRs by adding a ignored keyword in its title. Found: broken link.

You can change this by either removing the keyword above from the PR's title, or modifying the ignoreKeywords property in your Lunaria configuration file.

Tracked Files

Note

The notes below indicate what would happen if the pull request is merged when triggering status changes. Since a ignored keyword was found in the PR's title, the status changes indicated below won't be applied.

File	Note
en/tutorial/5-astro-api/1.mdx	Source changed, localizations will be marked as outdated.
en/tutorial/5-astro-api/2.mdx	Source changed, localizations will be marked as outdated.
en/tutorial/5-astro-api/3.mdx	Source changed, localizations will be marked as outdated.
en/tutorial/6-islands/4.mdx	Localization changed, will be marked as complete.

Warnings reference

Icon	Description
🔄️	The source for this localization has been updated since the creation of this pull request, make sure all changes in the source have been applied.

[sarah11918]

Great catches, thanks! And yes, we are still making high-value emergency fixes to 5.0 docs! Thank you very much for this!

[sarah11918]

I'm just rerunning the Netlify deploy to see if I can get it to work before merging. We're getting the "out of memory" error again.

[sarah11918]

Second Netlify deployment is fine! 🚀