[tutorial] new tutorial extensions

[sarah11918]

What kind of changes does this PR include?

• New or updated content

Description

This PR adds two ways to extend the existing tutorial. Both are walkthroughs starting from the existing blog tutorial codebase, but are written in a way to be more generally relevant (with caveats that if you're not using this starting code, you will need to make adjustments, and we suggest following these shorter tutorials to learn, then apply to your own project.)

1. Moves and updates the "Migrating from File-based Routing" section on the content collections page to display a more extensive version of mostly the same content here.

Preview: https://deploy-preview-4876--astro-docs-2.netlify.app/en/extend/add-content-collections/

2. Creates a visible CTA to update the blog tutorial to View Transitions, since this is what we would like our docs to emphasize. The content here is not yet written, and honestly doesn't have to be very much because it Just Works:tm: , but will probably add some specific transitions, route announcement etc. to show these off.

Preview: https://deploy-preview-4876--astro-docs-2.netlify.app/en/extend/add-view-transitions/

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[jonellwood]

View Transitions Opening Statement has a typo in "....page transitions and animations, controling the brower’s history stack of visited pages and...."

controlling should have 2 l's and I believe it should be browsers' history with the ' after the s not before.

Aaaaand I did not see the comments above mine that already pointed this out. My apologies. Also I need to learn how to do the cool Github diff thing in these comments. lol.

These are absolutely outstanding docs! Really well done and something to be quite proud of.

[freekrai]

Looks good aside from that one “controling” as previously mentioned. 👍

[bogdaaamn]

Left just two code suggestions, otherwise the content LGTM 🚀

[DarkidOP]

Typing mistake in collections tutorial

it should prolly be "This leads to.." instead of "the*

[cmdecker95]

Looks pretty good!

Here's a personal reword I would implement:

Current wording

'You can instead follow these steps with your own Astro project, but you will need to adjust the instructions for your codebase.'

Suggested wording

'Alternatively, you can follow along with your own Astro project. You'll just need to adjust the instructions for your codebase.'

I'd also consider putting "Build a Blog" in quotes so that it's a little clearer that there's a distinction:

Current wording

'Build a Blog Tutorial Code

In the Build a Blog introductory tutorial...'

Suggested wording

'"Build a Blog" Tutorial Code

In the "Build a Blog" introductory tutorial...'

[leowilkin]

Looks great. 🚀