Add Expressive Code <Code> component to Starlight

[hippotastic]

Description

• Adds the new <Code> component by Expressive Code to Starlight. For the original component, see here: https://expressive-code.com/key-features/code-component/
• Re-exports the component from Starlight to match the import syntax of all other user components:
  import { Code } from '@astrojs/starlight/components'
• Adds an @astrojs/starlight/internal export that provides access to the useTranslations function to components
• Changes the default behavior of the build:examples script so that the projects are no longer built concurrently. The previous configuration could lead to "Port already in use" errors, and building the examples sequentially fixes this.
• Adds documentation for the new component to the Components page

[changeset-bot]

🦋 Changeset detected

Latest commit: 02e30ed

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@astrojs/starlight	Minor

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Name	Status	Preview	Updated (UTC)
starlight	✅ Ready (Inspect)	Visit Preview	Jan 26, 2024 7:03pm

[delucis]

Super exciting to see you crack this challenging feature — I know so many of our users will be delighted to be able to use this. Thank you @hippotastic! Left a few comments, but I think it’s all small things and docs for the most part. The main feature seems to be working great! Amazing work 🙌

[delucis]

OK, added a changeset and will request one last docs check from @sarah11918, but otherwise looks good to go out tomorrow! Thanks @hippotastic 🚀

[hippotastic]

I'm happy with the Sarah-fied version!