fix(configuration-reference): remove page slug from internal anchor links

[ArmandPhilippot]

Description (required)

Fixes the docgen script to remove /en/reference/configuration-reference/ from internal anchor links.

The changes was introduced by withastro/astro#14411 because relative links do not work in editors.
Now, instead of [redirects](#redirects) we have [redirects](/en/reference/configuration-reference/#redirects) (for example).

Both works, but maybe we should clean the links as we do to make them relative instead of absolute?

(I don't have a strong opinion on this, it just seemed weird while I was updating the French translation. So feel free to tell me to close this one 😄 )

Related issues & labels (optional)

• Suggested label: site improvement?

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[sarah11918]

Thank you, Armand!

OK, so as I see it what happened was:

• [redirects](#redirects) in docgen produced valid links of the form [redirects](#redirects) in our configuration reference page. (yay!)
• however, [redirects](#redirects) in docgen meant that editor hover links in the editor didn't work (boo!)
• So, we changed the docgen source to read [redirects](/en/reference/configuration-reference/#redirects) which shows editor hover links (yay!) and produces valid links in our configuration reference page (yay!)
• however, now the links in the configuration source page are the longer [redirects](/en/reference/configuration-reference/#redirects) format (boo!)

So this PR would allow us to type [redirects](/en/reference/configuration-reference/#redirects) in the docgen source, but the resulting code imported into the docs repo for generating the page itself would be [redirects](#redirects). Did I get that summary correct?

I will let @delucis review this one when he returns! 😅

[ArmandPhilippot]

The formatting is broken, but after checking with "Edit": this is exactly that! 😅

[trueberryless]

Sarah, we need more yay!s:

So this PR would allow us to type [redirects](/en/reference/configuration-reference/#redirects) in the docgen source, but the resulting code imported into the docs repo for generating the page itself would be [redirects](#redirects).

(yay!)(yay!)

[delucis]

Code change LGTM! Did you try running this locally just to double check it works @ArmandPhilippot?

[ArmandPhilippot]

@delucis Yes! I checked again and didn't spotted any unwanted changes or oversights!

[delucis]

Perfect, then I approve! Thanks @ArmandPhilippot 🎉